dbus: move systemd-hooks for dbus.socket to 'dbus-common'

The systemd_{post,postun,preun,..} hooks should be called in the package
that actually provides the given files. There is no harm in calling
these in the dbus-daemon package, but preferably we don't. Move this to
'dbus-common' for dbus.socket, since dbus.socket is provided by it. This
makes sure the unit is properly enabled/disabled even without the
dbus-daemon package installed.

Note that it is safe to enable/disable dbus.socket even without a
dbus.service around. systemd can deal with this just fine, and only ever
actually pulls in the socket if an activatable service is around.

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>

dbus.spec

@@ -310,19 +310,31 @@ popd
 /usr/sbin/useradd -c 'System message bus' -u %{dbus_user_uid} -g %{dbus_user_uid} \
     -s /sbin/nologin -r -d '/' dbus 2> /dev/null || :
 
+%post common
+%systemd_post dbus.socket
+%systemd_user_post dbus.socket
+
 %post daemon
-%systemd_post dbus-daemon.service dbus.socket
-%systemd_user_post dbus-daemon.service dbus.socket
+%systemd_post dbus-daemon.service
+%systemd_user_post dbus-daemon.service
 
 %post libs -p /sbin/ldconfig
 
+%preun common
+%systemd_preun dbus.socket
+%systemd_user_preun dbus.socket
+
 %preun daemon
-%systemd_preun dbus-daemon.service dbus.socket
-%systemd_user_preun dbus-daemon.service dbus.socket
+%systemd_preun dbus-daemon.service
+%systemd_user_preun dbus-daemon.service
+
+%postun common
+%systemd_postun dbus.socket
+%systemd_user_postun dbus.socket
 
 %postun daemon
-%systemd_postun dbus-daemon.service dbus.socket
-%systemd_user_postun dbus-daemon.service dbus.socket
+%systemd_postun dbus-daemon.service
+%systemd_user_postun dbus-daemon.service
 
 %postun libs -p /sbin/ldconfig