libweston/launcher: use C99 initializers for the iface(s)

Makes the code easier to read and browse through.

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Reviewed-by: Daniel Stone <daniels@collabora.com>
diff --git a/libweston/launcher-direct.c b/libweston/launcher-direct.c
index 4e878a5..4195cf6 100644
--- a/libweston/launcher-direct.c
+++ b/libweston/launcher-direct.c
@@ -320,11 +320,11 @@
 }
 
 const struct launcher_interface launcher_direct_iface = {
-	launcher_direct_connect,
-	launcher_direct_destroy,
-	launcher_direct_open,
-	launcher_direct_close,
-	launcher_direct_activate_vt,
-	launcher_direct_restore,
-	launcher_direct_get_vt,
+	.connect = launcher_direct_connect,
+	.destroy = launcher_direct_destroy,
+	.open = launcher_direct_open,
+	.close = launcher_direct_close,
+	.activate_vt = launcher_direct_activate_vt,
+	.restore = launcher_direct_restore,
+	.get_vt = launcher_direct_get_vt,
 };