systemd: Tweak existing sysconf files

We're going to add many more later, so start by adjusting the
existing ones to more closely follow the example set by libvirtd.
Signed-off-by: NAndrea Bolognani <abologna@redhat.com>
Reviewed-by: NDaniel P. Berrangé <berrange@redhat.com>

src/locking/virtlockd.sysconf

-#
-# Pass extra arguments to virtlockd
-#VIRTLOCKD_ARGS=
+# Customizations for the virtlockd.service systemd unit
+
+VIRTLOCKD_ARGS=""

src/logging/virtlogd.sysconf

-#
-# Pass extra arguments to virtlogd
-#VIRTLOGD_ARGS=
+# Customizations for the virtlogd.service systemd unit
+
+VIRTLOGD_ARGS=""

tools/libvirt-guests.sysconf

+# Customizations for the libvirt-guests.service systemd unit
+
 # URIs to check for running guests
 # example: URIS='default xen:///system vbox+tcp://host/system lxc:///system'
 #URIS=default