compositor: Load modules with RTLD_NOW so we get missing symbols up front

Otherwise we have no way to clean up when we hit something undefined.
diff --git a/src/compositor.c b/src/compositor.c
index ed887a4..746ff85 100644
--- a/src/compositor.c
+++ b/src/compositor.c
@@ -3336,7 +3336,7 @@
 		snprintf(path, sizeof path, "%s", name);
 
 	weston_log("Loading module '%s'\n", path);
-	module = dlopen(path, RTLD_LAZY);
+	module = dlopen(path, RTLD_NOW);
 	if (!module) {
 		weston_log("Failed to load module: %s\n", dlerror());
 		return NULL;