treewide: Remove uninitialized_var() usage

Using uninitialized_var() is dangerous as it papers over real bugs[1]
(or can in the future), and suppresses unrelated compiler warnings
(e.g. "unused variable"). If the compiler thinks it is uninitialized,
either simply initialize the variable or make compiler changes.

In preparation for removing[2] the[3] macro[4], remove all remaining
needless uses with the following script:

git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \
	xargs perl -pi -e \
		's/\buninitialized_var\(([^\)]+)\)/\1/g;
		 s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;'

drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid
pathological white-space.

No outstanding warnings were found building allmodconfig with GCC 9.3.0
for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64,
alpha, and m68k.

[1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/
[2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/
[3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/
[4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/

Reviewed-by: Leon Romanovsky <leonro@mellanox.com> # drivers/infiniband and mlx4/mlx5
Acked-by: Jason Gunthorpe <jgg@mellanox.com> # IB
Acked-by: Kalle Valo <kvalo@codeaurora.org> # wireless drivers
Reviewed-by: Chao Yu <yuchao0@huawei.com> # erofs
Signed-off-by: Kees Cook <keescook@chromium.org>

fs/ocfs2/alloc.c

@@ -4707,7 +4707,7 @@ int ocfs2_insert_extent(handle_t *handle,
 			struct ocfs2_alloc_context *meta_ac)
 {
 	int status;
-	int uninitialized_var(free_records);
+	int free_records;
 	struct buffer_head *last_eb_bh = NULL;
 	struct ocfs2_insert_type insert = {0, };
 	struct ocfs2_extent_rec rec;
@@ -7051,7 +7051,7 @@ int ocfs2_convert_inline_data_to_extents(struct inode *inode,
 	int need_free = 0;
 	u32 bit_off, num;
 	handle_t *handle;
-	u64 uninitialized_var(block);
+	u64 block;
 	struct ocfs2_inode_info *oi = OCFS2_I(inode);
 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 	struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;

fs/ocfs2/dir.c

@@ -848,9 +848,9 @@ static int ocfs2_dx_dir_lookup(struct inode *inode,
 			       u64 *ret_phys_blkno)
 {
 	int ret = 0;
-	unsigned int cend, uninitialized_var(clen);
-	u32 uninitialized_var(cpos);
-	u64 uninitialized_var(blkno);
+	unsigned int cend, clen;
+	u32 cpos;
+	u64 blkno;
 	u32 name_hash = hinfo->major_hash;
 
 	ret = ocfs2_dx_dir_lookup_rec(inode, el, name_hash, &cpos, &blkno,
@@ -894,7 +894,7 @@ static int ocfs2_dx_dir_search(const char *name, int namelen,
 			       struct ocfs2_dir_lookup_result *res)
 {
 	int ret, i, found;
-	u64 uninitialized_var(phys);
+	u64 phys;
 	struct buffer_head *dx_leaf_bh = NULL;
 	struct ocfs2_dx_leaf *dx_leaf;
 	struct ocfs2_dx_entry *dx_entry = NULL;
@@ -4393,9 +4393,9 @@ out:
 int ocfs2_dx_dir_truncate(struct inode *dir, struct buffer_head *di_bh)
 {
 	int ret;
-	unsigned int uninitialized_var(clen);
-	u32 major_hash = UINT_MAX, p_cpos, uninitialized_var(cpos);
-	u64 uninitialized_var(blkno);
+	unsigned int clen;
+	u32 major_hash = UINT_MAX, p_cpos, cpos;
+	u64 blkno;
 	struct ocfs2_super *osb = OCFS2_SB(dir->i_sb);
 	struct buffer_head *dx_root_bh = NULL;
 	struct ocfs2_dx_root_block *dx_root;

fs/ocfs2/extent_map.c

@@ -403,7 +403,7 @@ static int ocfs2_get_clusters_nocache(struct inode *inode,
 {
 	int i, ret, tree_height, len;
 	struct ocfs2_dinode *di;
-	struct ocfs2_extent_block *uninitialized_var(eb);
+	struct ocfs2_extent_block *eb;
 	struct ocfs2_extent_list *el;
 	struct ocfs2_extent_rec *rec;
 	struct buffer_head *eb_bh = NULL;
@@ -599,7 +599,7 @@ int ocfs2_get_clusters(struct inode *inode, u32 v_cluster,
 		       unsigned int *extent_flags)
 {
 	int ret;
-	unsigned int uninitialized_var(hole_len), flags = 0;
+	unsigned int hole_len, flags = 0;
 	struct buffer_head *di_bh = NULL;
 	struct ocfs2_extent_rec rec;
 

fs/ocfs2/namei.c

@@ -2498,7 +2498,7 @@ int ocfs2_create_inode_in_orphan(struct inode *dir,
 	struct buffer_head *new_di_bh = NULL;
 	struct ocfs2_alloc_context *inode_ac = NULL;
 	struct ocfs2_dir_lookup_result orphan_insert = { NULL, };
-	u64 uninitialized_var(di_blkno), suballoc_loc;
+	u64 di_blkno, suballoc_loc;
 	u16 suballoc_bit;
 
 	status = ocfs2_inode_lock(dir, &parent_di_bh, 1);

fs/ocfs2/refcounttree.c

@@ -1063,7 +1063,7 @@ static int ocfs2_get_refcount_rec(struct ocfs2_caching_info *ci,
 				  struct buffer_head **ret_bh)
 {
 	int ret = 0, i, found;
-	u32 low_cpos, uninitialized_var(cpos_end);
+	u32 low_cpos, cpos_end;
 	struct ocfs2_extent_list *el;
 	struct ocfs2_extent_rec *rec = NULL;
 	struct ocfs2_extent_block *eb = NULL;

fs/ocfs2/xattr.c

@@ -1211,7 +1211,7 @@ static int ocfs2_xattr_block_get(struct inode *inode,
 	struct ocfs2_xattr_value_root *xv;
 	size_t size;
 	int ret = -ENODATA, name_offset, name_len, i;
-	int uninitialized_var(block_off);
+	int block_off;
 
 	xs->bucket = ocfs2_xattr_bucket_new(inode);
 	if (!xs->bucket) {