iser: set sector for ambiguous mr status errors

If for some reason we failed to query the mr status, we need to make sure
to provide sufficient information for an ambiguous error (guard error on
sector 0).

Fixes: 0a7a08ad ("IB/iser: Implement check_protection")
Cc: <stable@vger.kernel.org>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/ulp/iser/iser_verbs.c

@@ -1124,7 +1124,9 @@ u8 iser_check_task_pi_status(struct iscsi_iser_task *iser_task,
 					 IB_MR_CHECK_SIG_STATUS, &mr_status);
 		if (ret) {
 			pr_err("ib_check_mr_status failed, ret %d\n", ret);
-			goto err;
+			/* Not a lot we can do, return ambiguous guard error */
+			*sector = 0;
+			return 0x1;
 		}
 
 		if (mr_status.fail_status & IB_MR_CHECK_SIG_STATUS) {
@@ -1152,9 +1154,6 @@ u8 iser_check_task_pi_status(struct iscsi_iser_task *iser_task,
 	}
 
 	return 0;
-err:
-	/* Not alot we can do here, return ambiguous guard error */
-	return 0x1;
 }
 
 void iser_err_comp(struct ib_wc *wc, const char *type)