staging: lustre: fix checkpatch error

convert spaces to tab

fix the following error messages from checkpatch.pl

ERROR: code indent should use tabs where possible
WARNING: please, no spaces at the start of a line
Signed-off-by: Anson Jacob <ansonjacob.aj@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/lustre/include/cl_object.h

@@ -2351,7 +2351,7 @@ struct cl_client_cache {
 	 * Waitq for awaiting unstable pages to reach zero.
 	 * Used at umounting time and signaled on BRW commit
 	 */
-        wait_queue_head_t	ccc_unstable_waitq;
+	wait_queue_head_t	ccc_unstable_waitq;
 
 };