launcher: Rename logind-util to launcher-logind

We're refactoring this to have multiple launcher "implementations".

Reviewed-by: Derek Foreman <derekf@osg.samsung.com>

src/launcher-logind.c

@@ -44,7 +44,7 @@
 
 #include "compositor.h"
 #include "dbus.h"
-#include "logind-util.h"
+#include "launcher-logind.h"
 
 #define DRM_MAJOR 226
 

src/launcher-util.c

@@ -45,7 +45,7 @@
 
 #include "compositor.h"
 #include "launcher-util.h"
-#include "logind-util.h"
+#include "launcher-logind.h"
 #include "weston-launch.h"
 
 #define DRM_MAJOR 226