igb: fix setting the number of tx queues

The real_num_tx_queues was not being set when in MSI-X only mode.  This patch
corrects that path so all interrupt types are correctly configured.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

drivers/net/igb/igb_main.c

@@ -521,7 +521,7 @@ static void igb_set_interrupt_capability(struct igb_adapter *adapter)
 			      adapter->msix_entries,
 			      numvecs);
 	if (err == 0)
-		return;
+		goto out;
 
 	igb_reset_interrupt_capability(adapter);
 
@@ -531,7 +531,7 @@ msi_only:
 	adapter->num_tx_queues = 1;
 	if (!pci_enable_msi(adapter->pdev))
 		adapter->flags |= IGB_FLAG_HAS_MSI;
-
+out:
 	/* Notify the stack of the (possibly) reduced Tx Queue count. */
 	adapter->netdev->real_num_tx_queues = adapter->num_tx_queues;
 	return;