KVM: s390: implementation of kvm_arch_vcpu_runnable()

A vcpu is defined to be runnable if an interrupt is pending.

Signed-off-by: Michael Mueller <mimu@linux.vnet.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/s390/kvm/kvm-s390.c

@@ -483,9 +483,7 @@ out:
 
 int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu)
 {
-	/* kvm common code refers to this, but never calls it */
-	BUG();
-	return 0;
+	return kvm_cpu_has_interrupt(vcpu);
 }
 
 void s390_vcpu_block(struct kvm_vcpu *vcpu)