virtlockd: fix socket path

Change the socket path to match the one used by lockd driver.

https://bugzilla.redhat.com/show_bug.cgi?id=968128

src/locking/virtlockd.socket.in

@@ -2,7 +2,7 @@
 Description=Virtual machine lock manager socket
 
 [Socket]
-ListenStream=@localstatedir@/run/libvirt/virtlockd/virtlockd.sock
+ListenStream=@localstatedir@/run/libvirt/virtlockd-sock
 
 [Install]
 WantedBy=multi-user.target