render/egl: remove SURFACELESS_MESA special case

Users can just pass EGL_DEFAULT_DISPLAY themselves.

backend/headless/backend.c

@@ -113,7 +113,8 @@ struct wlr_backend *wlr_headless_backend_create(struct wl_display *display,
 	}
 
 	backend->renderer = create_renderer_func(&backend->egl,
-		EGL_PLATFORM_SURFACELESS_MESA, NULL, (EGLint*)config_attribs, 0);
+		EGL_PLATFORM_SURFACELESS_MESA, EGL_DEFAULT_DISPLAY,
+		(EGLint*)config_attribs, 0);
 	if (!backend->renderer) {
 		wlr_log(WLR_ERROR, "Failed to create renderer");
 		free(backend);

render/egl.c

@@ -170,14 +170,8 @@ bool wlr_egl_init(struct wlr_egl *egl, EGLenum platform, void *remote_display,
 		goto error;
 	}
 
-	if (platform == EGL_PLATFORM_SURFACELESS_MESA) {
-		assert(remote_display == NULL);
-		egl->display = egl->procs.eglGetPlatformDisplayEXT(platform,
-			EGL_DEFAULT_DISPLAY, NULL);
-	} else {
-		egl->display = egl->procs.eglGetPlatformDisplayEXT(platform,
-			remote_display, NULL);
-	}
+	egl->display = egl->procs.eglGetPlatformDisplayEXT(platform,
+		remote_display, NULL);
 	if (egl->display == EGL_NO_DISPLAY) {
 		wlr_log(WLR_ERROR, "Failed to create EGL display");
 		goto error;