bnx2x: save RAM in kdump kernel by using a single queue

When running in a kdump kernel, make sure to use only a single ethernet
queue even if a num_queues option in /etc/modprobe.d/*.conf would specify
otherwise. This saves memory, which tends to be scarce in kdump.

This saves about 40 MB in the kdump environment on a setup with
num_queues=8 in the config file.
Signed-off-by: Michal Schmidt <mschmidt@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c

@@ -62,6 +62,11 @@ static void bnx2x_add_all_napi(struct bnx2x *bp)
 static int bnx2x_calc_num_queues(struct bnx2x *bp)
 {
 	int nq = bnx2x_num_queues ? : netif_get_num_default_rss_queues();
+
+	/* Reduce memory usage in kdump environment by using only one queue */
+	if (reset_devices)
+		nq = 1;
+
 	nq = clamp(nq, 1, BNX2X_MAX_QUEUES(bp));
 	return nq;
 }