e1000: Don't enable polling in open() (was: e1000: assertion hit in e1000_clean(), kernel 2.6.21.1)

Herbert Xu wrote:
"netif_poll_enable can only be called if you've previously called
netif_poll_disable.  Otherwise a poll might already be in action
and you may get a crash like this."

Removing the call to netif_poll_enable in e1000_open should fix this issue,
the only other call to netif_poll_enable is in e1000_up() which is only
reached after a device reset or resume.

Bugzilla: http://bugzilla.kernel.org/show_bug.cgi?id=8455
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=240339

Tested by Doug Chapman <doug.chapman@hp.com>

Signed-off-by: Auke Kok <auke-jan.h.kok@intel.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

drivers/net/e1000/e1000_main.c

@@ -1431,10 +1431,6 @@ e1000_open(struct net_device *netdev)
 	/* From here on the code is the same as e1000_up() */
 	clear_bit(__E1000_DOWN, &adapter->flags);
 
-#ifdef CONFIG_E1000_NAPI
-	netif_poll_enable(netdev);
-#endif
-
 	e1000_irq_enable(adapter);
 
 	/* fire a link status change interrupt to start the watchdog */