[TG3]: Flush tg3_reset_task()

Make sure tg3_reset_task() is flushed in the close and suspend paths
as noted by Jeff Garzik.

In the close path, calling flush_scheduled_work() may cause deadlock
if linkwatch_event() is on the workqueue. linkwatch_event() will try
to get the rtnl_lock() which is already held by tg3_close(). So
instead, we set a flag in tg3_reset_task() and tg3_close() polls
the flag until it is cleared.

Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/tg3.h b/drivers/net/tg3.h
index e824330..7f4b7f6 100644
--- a/drivers/net/tg3.h
+++ b/drivers/net/tg3.h
@@ -2162,6 +2162,7 @@
 #define TG3_FLAG_JUMBO_RING_ENABLE	0x00800000
 #define TG3_FLAG_10_100_ONLY		0x01000000
 #define TG3_FLAG_PAUSE_AUTONEG		0x02000000
+#define TG3_FLAG_IN_RESET_TASK		0x04000000
 #define TG3_FLAG_BROKEN_CHECKSUMS	0x10000000
 #define TG3_FLAG_GOT_SERDES_FLOWCTL	0x20000000
 #define TG3_FLAG_SPLIT_MODE		0x40000000