net: adjust napi_consume_skb to handle non-NAPI callers

Some drivers reuse/share code paths that free SKBs between NAPI
and non-NAPI calls. Adjust napi_consume_skb to handle this
use-case.

Before, calls from netpoll (w/ IRQs disabled) was handled and
indicated with a budget zero indication.  Use the same zero
indication to handle calls not originating from NAPI/softirq.
Simply handled by using dev_consume_skb_any().

This adds an extra branch+call for the netpoll case (checking
in_irq() + irqs_disabled()), but that is okay as this is a slowpath.

Suggested-by: Alexander Duyck <aduyck@mirantis.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>