KVM: s390: cleanup handle_wait by reusing kvm_vcpu_block

KVM: s390: cleanup handle_wait by reusing kvm_vcpu_block

This patch cleans up the code in handle_wait by reusing the common code
function kvm_vcpu_block.

signal_pending(), kvm_cpu_has_pending_timer() and kvm_arch_vcpu_runnable() are
sufficient for checking if we need to wake-up that VCPU. kvm_vcpu_block
uses these functions, so no checks are lost.

The flag "timer_due" can be removed - kvm_cpu_has_pending_timer() tests whether
the timer is pending, thus the vcpu is correctly woken up.

Signed-off-by: David Hildenbrand <[email protected]>
Acked-by: Christian Borntraeger <[email protected]>
Acked-by: Cornelia Huck <[email protected]>
Signed-off-by: Christian Borntraeger <[email protected]>