ceph: change variable name to follow common rule

Variable name ci is mostly used for ceph_inode_info.
Variable name fi is mostly used for ceph_file_info.
Variable name cf is mostly used for ceph_cap_flush.

Change variable name to follow above common rules
in case of confusing.

Signed-off-by: Chengguang Xu <cgxu519@icloud.com>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

fs/ceph/addr.c

@@ -439,7 +439,7 @@ static int ceph_readpages(struct file *file, struct address_space *mapping,
 {
 	struct inode *inode = file_inode(file);
 	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
-	struct ceph_file_info *ci = file->private_data;
+	struct ceph_file_info *fi = file->private_data;
 	struct ceph_rw_context *rw_ctx;
 	int rc = 0;
 	int max = 0;
@@ -453,7 +453,7 @@ static int ceph_readpages(struct file *file, struct address_space *mapping,
 	if (rc == 0)
 		goto out;
 
-	rw_ctx = ceph_find_rw_context(ci);
+	rw_ctx = ceph_find_rw_context(fi);
 	max = fsc->mount_options->rsize >> PAGE_SHIFT;
 	dout("readpages %p file %p ctx %p nr_pages %d max %d\n",
 	     inode, file, rw_ctx, nr_pages, max);