KVM: s390: add exit io request stats and simplify code

We want to count IO exit requests in kvm_stat. At the same time
we can get rid of the handle_noop function.

Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

arch/s390/include/asm/kvm_host.h

@@ -294,6 +294,7 @@ struct kvm_vcpu_stat {
 	u64 exit_userspace;
 	u64 exit_null;
 	u64 exit_external_request;
+	u64 exit_io_request;
 	u64 exit_external_interrupt;
 	u64 exit_stop_request;
 	u64 exit_validity;