compositor: Remove deprecated xwayland loading method

This is awkward and long deprecated, and makes us load xwayland after all
the other modules so we know if we have to load it or not. Let's remove it.

We do still need to prevent loading the module the wrong way, though.

Signed-off-by: Derek Foreman <derek.foreman@collabora.com>

compositor/main.c

@@ -989,7 +989,7 @@ wet_get_bindir_path(const char *name)
 
 static int
 load_modules(struct weston_compositor *ec, const char *modules,
-	     int *argc, char *argv[], bool *xwayland)
+	     int *argc, char *argv[])
 {
 	const char *p, *end;
 	char buffer[256];
@@ -1003,11 +1003,11 @@ load_modules(struct weston_compositor *ec, const char *modules,
 		snprintf(buffer, sizeof buffer, "%.*s", (int) (end - p), p);
 
 		if (strstr(buffer, "xwayland.so")) {
-			weston_log("Old Xwayland module loading detected: "
+			weston_log("fatal: Old Xwayland module loading detected: "
 				   "Please use --xwayland command line option "
 				   "or set xwayland=true in the [core] section "
 				   "in weston.ini\n");
-			*xwayland = true;
+			return -1;
 		} else {
 			if (wet_load_module(ec, buffer, argc, argv) < 0)
 				return -1;
@@ -3730,10 +3730,10 @@ wet_main(int argc, char *argv[], const struct weston_testsuite_data *test_data)
 		goto out;
 
 	weston_config_section_get_string(section, "modules", &modules, "");
-	if (load_modules(wet.compositor, modules, &argc, argv, &xwayland) < 0)
+	if (load_modules(wet.compositor, modules, &argc, argv) < 0)
 		goto out;
 
-	if (load_modules(wet.compositor, option_modules, &argc, argv, &xwayland) < 0)
+	if (load_modules(wet.compositor, option_modules, &argc, argv) < 0)
 		goto out;
 
 	if (!xwayland) {