[PATCH] s2io: init/shutdown fixes

Hi,
	The following patch contains fix related to init and shutdown of adapter
	as per user guide.  The list of changes include

	1. shutdown gracefully.
	2. Need to mask/unmask interrupts in ISR required fro Xframe-E
	3. Tx FIFO should be enabled after WRR calender programming

Signed-off-by: Ananda Raju <ananda.raju@neterion.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>