qemu: Map running reason to resume event detail

qemu: Map running reason to resume event detail

Thanks to the previous commit the RESUME event handler knows what reason
should be used when changing the domain state to VIR_DOMAIN_RUNNING, but
the emitted VIR_DOMAIN_EVENT_RESUMED event still uses a generic
VIR_DOMAIN_EVENT_RESUMED_UNPAUSED detail. Luckily, the event detail can
be easily deduced from the running reason, which saves us from having to
pass one more value to the handler.

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