ovl: fix some kernel-doc comments

Remove warnings found by running scripts/kernel-doc,
which is caused by using 'make W=1'.
fs/overlayfs/super.c:311: warning: Function parameter or member 'dentry'
not described in 'ovl_statfs'
fs/overlayfs/super.c:311: warning: Excess function parameter 'sb'
description in 'ovl_statfs'
fs/overlayfs/super.c:357: warning: Function parameter or member 'm' not
described in 'ovl_show_options'
fs/overlayfs/super.c:357: warning: Function parameter or member 'dentry'
not described in 'ovl_show_options'

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

fs/overlayfs/super.c

@@ -301,7 +301,7 @@ static int ovl_sync_fs(struct super_block *sb, int wait)
 
 /**
  * ovl_statfs
- * @sb: The overlayfs super block
+ * @dentry: The dentry to query
  * @buf: The struct kstatfs to fill in with stats
  *
  * Get the filesystem statistics.  As writes always target the upper layer
@@ -349,6 +349,8 @@ static inline int ovl_xino_def(void)
 
 /**
  * ovl_show_options
+ * @m: the seq_file handle
+ * @dentry: The dentry to query
  *
  * Prints the mount options for a given superblock.
  * Returns zero; does not fail.