compositor-drm: Retrieve extension functions before wlsc_compositor_init

wlsc_compositor_init calls pointer_create, which calls
create_cursor which needs EGL_MESA_drm_image functions.

compositor/compositor-drm.c

@@ -702,15 +702,15 @@ drm_compositor_create(struct wl_display *display, int connector)
 	glGenFramebuffers(1, &ec->base.fbo);
 	glBindFramebuffer(GL_FRAMEBUFFER, ec->base.fbo);
 
-	/* Can't init base class until we have a current egl context */
-	if (wlsc_compositor_init(&ec->base, display) < 0)
-		return NULL;
-
 	ec->create_drm_image =
 		(void *) eglGetProcAddress("eglCreateDRMImageMESA");
 	ec->export_drm_image =
 		(void *) eglGetProcAddress("eglExportDRMImageMESA");
 
+	/* Can't init base class until we have a current egl context */
+	if (wlsc_compositor_init(&ec->base, display) < 0)
+		return NULL;
+
 	if (create_outputs(ec, connector) < 0) {
 		fprintf(stderr, "failed to create output for %s\n", path);
 		return NULL;