[TG3]: Fix crash during tg3_init_one().

The driver will crash when the chip has been initialized by EFI before
tg3_init_one().  In this case, the driver will call tg3_chip_reset()
before allocating consistent memory.

The bug is fixed by checking for tp->hw_status before accessing it
during tg3_chip_reset().
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/tg3.c

@@ -4834,8 +4834,10 @@ static int tg3_chip_reset(struct tg3 *tp)
 	 * sharing or irqpoll.
 	 */
 	tp->tg3_flags |= TG3_FLAG_CHIP_RESETTING;
+	if (tp->hw_status) {
 		tp->hw_status->status = 0;
 		tp->hw_status->status_tag = 0;
+	}
 	tp->last_tag = 0;
 	smp_mb();
 	synchronize_irq(tp->pdev->irq);