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>