kernfs: s/sysfs/kernfs/ in global variables

kernfs has just been separated out from sysfs and we're already in
full conflict mode.  Nothing can make the situation any worse.  Let's
take the chance to name things properly.

This patch performs the following renames.

* s/sysfs_mutex/kernfs_mutex/
* s/sysfs_dentry_ops/kernfs_dops/
* s/sysfs_dir_operations/kernfs_dir_fops/
* s/sysfs_dir_inode_operations/kernfs_dir_iops/
* s/kernfs_file_operations/kernfs_file_fops/ - renamed for consistency
* s/sysfs_symlink_inode_operations/kernfs_symlink_iops/
* s/sysfs_aops/kernfs_aops/
* s/sysfs_backing_dev_info/kernfs_bdi/
* s/sysfs_inode_operations/kernfs_iops/
* s/sysfs_dir_cachep/kernfs_node_cache/
* s/sysfs_ops/kernfs_sops/

This patch is strictly rename only and doesn't introduce any
functional difference.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/fs/kernfs/file.c b/fs/kernfs/file.c
index abe93e1..32364dd 100644
--- a/fs/kernfs/file.c
+++ b/fs/kernfs/file.c
@@ -750,7 +750,7 @@
 }
 EXPORT_SYMBOL_GPL(kernfs_notify);
 
-const struct file_operations kernfs_file_operations = {
+const struct file_operations kernfs_file_fops = {
 	.read		= kernfs_file_read,
 	.write		= kernfs_file_write,
 	.llseek		= generic_file_llseek,