bnx2: Don't receive packets when the napi budget == 0

Processing any incoming packets with a with a napi budget of 0
is incorrect driver behavior.

This matters as netpoll will shortly call drivers with a budget of 0
to avoid receive packet processing happening in hard irq context.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bnx2.c

@@ -3132,6 +3132,9 @@ bnx2_rx_int(struct bnx2 *bp, struct bnx2_napi *bnapi, int budget)
 	struct l2_fhdr *rx_hdr;
 	int rx_pkt = 0, pg_ring_used = 0;
 
+	if (budget <= 0)
+		return rx_pkt;
+
 	hw_cons = bnx2_get_hw_rx_cons(bnapi);
 	sw_cons = rxr->rx_cons;
 	sw_prod = rxr->rx_prod;