Staging: lustre: Fix checkpatch error: Unnecessary comparison

Removed unnecessary comparison against NULL to remove following
checkpatch error:

ERROR: spaces required around that '!='
Signed-off-by: Tina Johnson <tinajohnson.1234@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/lustre/llite/llite_lib.c

@@ -1122,7 +1122,7 @@ void ll_put_super(struct super_block *sb)
 	}
 
 	next = 0;
-	while ((obd = class_devices_in_group(&sbi->ll_sb_uuid, &next)) !=NULL)
+	while ((obd = class_devices_in_group(&sbi->ll_sb_uuid, &next)))
 		class_manual_cleanup(obd);
 
 	if (sbi->ll_flags & LL_SBI_VERBOSE)