virtlogd: Don't stop or restart along with libvirtd

Commit 839a0608 tied the lifecycle of virtlogd more
closely to that of libvirtd. Unfortunately, while starting
virtlogd when libvirtd is started is definitely a good idea,
restarting virtlogd or shutting it down at any time outside
of system poweroff is not.

Revert part of that commit by removing the PartOf= lines,
meaning that only startup requests will be propagated from
libvirtd to virtlogd.

Resolves: https://bugzilla.redhat.com/1372576
(cherry picked from commit f496ce1d)

src/logging/virtlogd.service.in

@@ -2,7 +2,6 @@
 Description=Virtual machine log manager
 Requires=virtlogd.socket
 Before=libvirtd.service
-PartOf=libvirtd.service
 Documentation=man:virtlogd(8)
 Documentation=http://libvirt.org
 

src/logging/virtlogd.socket.in

 [Unit]
 Description=Virtual machine log manager socket
 Before=libvirtd.service
-PartOf=libvirtd.service
 
 [Socket]
 ListenStream=@localstatedir@/run/libvirt/virtlogd-sock