Don't depend on syslog.service

Syslog is socket activated since at least systemd v35 so we can drop
this dependency. Debian's linitian otherwise complains about it.

References:

    http://www.freedesktop.org/wiki/Software/systemd/syslog/
    http://lintian.debian.org/tags/systemd-service-file-refers-to-obsolete-target.html

src/locking/virtlockd.service.in

 [Unit]
 Description=Virtual machine lock manager
 Requires=virtlockd.socket
-After=syslog.target
 
 [Service]
 EnvironmentFile=-/etc/sysconfig/virtlockd

tools/libvirt-guests.service.in

 [Unit]
 Description=Suspend Active Libvirt Guests
-After=syslog.target network.target
+After=network.target
 
 [Service]
 EnvironmentFile=-/etc/sysconfig/libvirt-guests