staging: lustre: checking for NULL instead of IS_ERR

lustre_cfg_new() returns error pointers on error, it never returns NULL.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/lustre/mgc/mgc_request.c

@@ -1282,7 +1282,7 @@ static int mgc_apply_recover_logs(struct obd_device *mgc,
 
 		rc = -ENOMEM;
 		lcfg = lustre_cfg_new(LCFG_PARAM, &bufs);
-		if (!lcfg) {
+		if (IS_ERR(lcfg)) {
 			CERROR("mgc: cannot allocate memory\n");
 			break;
 		}