f2fs: get rid of fake on-stack dentries

those should never be used for a lot of reasons...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/f2fs/f2fs.h

@@ -868,11 +868,17 @@ ino_t f2fs_inode_by_name(struct inode *, struct qstr *);
 void f2fs_set_link(struct inode *, struct f2fs_dir_entry *,
 				struct page *, struct inode *);
 void init_dent_inode(const struct qstr *, struct page *);
-int f2fs_add_link(struct dentry *, struct inode *);
+int __f2fs_add_link(struct inode *, const struct qstr *, struct inode *);
 void f2fs_delete_entry(struct f2fs_dir_entry *, struct page *, struct inode *);
 int f2fs_make_empty(struct inode *, struct inode *);
 bool f2fs_empty_dir(struct inode *);
 
+static inline int f2fs_add_link(struct dentry *dentry, struct inode *inode)
+{
+	return __f2fs_add_link(dentry->d_parent->d_inode, &dentry->d_name,
+				inode);
+}
+
 /*
  * super.c
  */