cxgb4: fix error return code in cxgb4_set_hash_filter()

Fix to return a negative error code from thecxgb4_alloc_atid()
error handling case instead of 0.

Fixes: 12b276fb ("cxgb4: add support to create hash filters")
Signed-off-by: NWei Yongjun <weiyongjun1@huawei.com>
Acked-By: NKumar Sanghvi <kumaras@chelsio.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/chelsio/cxgb4/cxgb4_filter.c

@@ -1110,8 +1110,10 @@ static int cxgb4_set_hash_filter(struct net_device *dev,
 	}
 
 	atid = cxgb4_alloc_atid(t, f);
-	if (atid < 0)
+	if (atid < 0) {
+		ret = atid;
 		goto free_smt;
+	}
 
 	iconf = adapter->params.tp.ingress_config;
 	if (iconf & VNIC_F) {