s390x/kvm: cleanup calls to cpu_synchronize_state()

s390x/kvm: cleanup calls to cpu_synchronize_state()

We have a call to cpu_synchronize_state() on every kvm_arch_handle_exit().

Let's remove the ones that are no longer needed.

Remaining places (for s390x) are in
- target/s390x/sigp.c, on the target CPU
- target/s390x/cpu.c:s390_cpu_get_crash_info()

While at it, use kvm_cpu_synchronize_state() instead of
cpu_synchronize_state() in KVM code. (suggested by Thomas Huth)

Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20180412093521.2469-1-david@redhat.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>