be2net: post full RXQ on interface enable

When an RXQ is created in be_open(), the driver currently posts only
64 buffers. This sometimes results in packet drops when there is a traffic
burst as soon as the interface is enabled.
This patch fixes this problem by posting the full RXQ on interface enable.

Signed-off-by: Suresh Reddy <Suresh.Reddy@avagotech.com>
Signed-off-by: Sathya Perla <sathya.perla@avagotech.com>
Signed-off-by: David S. Miller <davem@davemloft.net>