fs/dlm/debug_fs.c: remove unnecessary null test before debugfs_remove

This fixes checkpatch warning:

  WARNING: debugfs_remove(NULL) is safe this check is probably not required
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Christine Caulfield <ccaulfie@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/dlm/debug_fs.c

@@ -718,15 +718,10 @@ static const struct file_operations waiters_fops = {
 
 void dlm_delete_debug_file(struct dlm_ls *ls)
 {
-	if (ls->ls_debug_rsb_dentry)
 	debugfs_remove(ls->ls_debug_rsb_dentry);
-	if (ls->ls_debug_waiters_dentry)
 	debugfs_remove(ls->ls_debug_waiters_dentry);
-	if (ls->ls_debug_locks_dentry)
 	debugfs_remove(ls->ls_debug_locks_dentry);
-	if (ls->ls_debug_all_dentry)
 	debugfs_remove(ls->ls_debug_all_dentry);
-	if (ls->ls_debug_toss_dentry)
 	debugfs_remove(ls->ls_debug_toss_dentry);
 }