Replace disable_irq() which waits for threaded irq handlers with
disable_hardirq() which waits only for hardirq part.

Fixes: 31119129 ("e1000: use disable_hardirq() for e1000_netpoll()")
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>