cxgb3: fix error return code in t3_sge_alloc_qset()

Fix to return a negative error code from the error handling
case instead of 0, as done elsewhere in this function.

Fixes: b1fb1f2 ("cxgb3 - Fix dma mapping error path")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Acked-by: Raju Rangoju <rajur@chelsio.com>
Link: https://lore.kernel.org/r/1606902965-1646-1-git-send-email-zhangchangzhong@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/chelsio/cxgb3/sge.c

@@ -3175,6 +3175,7 @@ int t3_sge_alloc_qset(struct adapter *adapter, unsigned int id, int nports,
 			  GFP_KERNEL | __GFP_COMP);
 	if (!avail) {
 		CH_ALERT(adapter, "free list queue 0 initialization failed\n");
+		ret = -ENOMEM;
 		goto err;
 	}
 	if (avail < q->fl[0].size)