fbnic: Set napi irq value after calling netif_napi_add

The driver calls netif_napi_set_irq() and then calls netif_napi_add(),
which calls netif_napi_add_weight(). At the end of
netif_napi_add_weight() is a call to netif_napi_set_irq(napi, -1), which
clears the previously set napi->irq value. Fix this by calling
netif_napi_set_irq() after calling netif_napi_add().

This was found when reviewing another patch and I have no way to test
this, but the fix seemed relatively straight forward.

Fixes: bc610777 ("eth: fbnic: Allocate a netdevice and napi vectors with queues")
Signed-off-by: Brett Creeley <brett.creeley@amd.com>
Reviewed-by: Joe Damato <jdamato@fastly.com>
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Link: https://patch.msgid.link/20240912174922.10550-1-brett.creeley@amd.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/meta/fbnic/fbnic_txrx.c

@@ -1012,14 +1012,14 @@ static int fbnic_alloc_napi_vector(struct fbnic_dev *fbd, struct fbnic_net *fbn,
 	nv->fbd = fbd;
 	nv->v_idx = v_idx;
 
-	/* Record IRQ to NAPI struct */
-	netif_napi_set_irq(&nv->napi,
-			   pci_irq_vector(to_pci_dev(fbd->dev), nv->v_idx));
-
 	/* Tie napi to netdev */
 	list_add(&nv->napis, &fbn->napis);
 	netif_napi_add(fbn->netdev, &nv->napi, fbnic_poll);
 
+	/* Record IRQ to NAPI struct */
+	netif_napi_set_irq(&nv->napi,
+			   pci_irq_vector(to_pci_dev(fbd->dev), nv->v_idx));
+
 	/* Tie nv back to PCIe dev */
 	nv->dev = fbd->dev;