cxgb4: Fix an error code in cxgb4_mqprio_alloc_hw_resources()

"ret" is zero or possibly uninitialized on this error path.  It
should be a negative error code instead.

Fixes: 2d0cb84 ("cxgb4: add ETHOFLD hardware queue support")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/chelsio/cxgb4/cxgb4_tc_mqprio.c

@@ -158,8 +158,10 @@ static int cxgb4_mqprio_alloc_hw_resources(struct net_device *dev)
 		/* Allocate Rxqs for receiving ETHOFLD Tx completions */
 		if (msix >= 0) {
 			msix = cxgb4_get_msix_idx_from_bmap(adap);
-			if (msix < 0)
+			if (msix < 0) {
+				ret = msix;
 				goto out_free_queues;
+			}
 
 			eorxq->msix = &adap->msix_info[msix];
 			snprintf(eorxq->msix->desc,