Fix TX Pause bug (reset_tx, intr_handler).  When MaxCollisions occurred, need
to re-enable Tx.  But just after re-enable, MaxCollisions maybe occurred again
and with TxStatusOverflow.  This will cause driver can't check new
MaxCollisions to re-enable Tx again, because TxStatusOverflow.  For this
reason, after re-enable Tx, we need to make sure Tx was actually enabled.
Signed-off-by: NJesse Huang <jesse@icplus.com.tw>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NJeff Garzik <jeff@garzik.org>