kvm: Leave kvm_cpu_exec directly after KVM_EXIT_SHUTDOWN

The reset we issue on KVM_EXIT_SHUTDOWN implies that we should also
leave the VCPU loop. As we now check for exit_request which is set by
qemu_system_reset_request, this bug is no longer critical. Still it's an
unneeded extra turn.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

kvm-all.c

@@ -963,7 +963,6 @@ int kvm_cpu_exec(CPUState *env)
         case KVM_EXIT_SHUTDOWN:
             DPRINTF("shutdown\n");
             qemu_system_reset_request();
-            ret = 1;
             break;
         case KVM_EXIT_UNKNOWN:
             fprintf(stderr, "KVM: unknown exit, hardware reason %" PRIx64 "\n",