fbnic: Set napi irq value after calling netif_napi_add

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: bc6107771bb4 ("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.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>