kvm/eventfd: avoid loop inside irqfd_update()

kvm/eventfd: avoid loop inside irqfd_update()

The loop(for) inside irqfd_update() is unnecessary
because any other value for irq_entry.type will just trigger
schedule_work(&irqfd->inject) in irqfd_wakeup.

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Vitaly Kuznetsov <vkuznets@redhat.com>
CC: "K. Y. Srinivasan" <kys@microsoft.com>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>