qemu: Drop unreachable code from qemuProcessHandleStop

qemu: Drop unreachable code from qemuProcessHandleStop

If gotShutdown is true, the domain state cannot be running because of
the following code in qemuProcessHandleShutdown:

    priv->gotShutdown = true;

    VIR_DEBUG("Transitioned guest %s to shutdown state",
              vm->def->name);
    virDomainObjSetState(vm,
                         VIR_DOMAIN_SHUTDOWN,
                         VIR_DOMAIN_SHUTDOWN_UNKNOWN);

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>