drm/panel/panel-sitronix-st7701: Remove panel on DSI attach failure

In case mipi_dsi_attach() fails, call drm_panel_remove() to
avoid memory leak.

Fixes: 849b2e3f ("drm/panel: Add Sitronix ST7701 panel driver")
Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20221014231106.468063-1-marex@denx.de

drivers/gpu/drm/panel/panel-sitronix-st7701.c

@@ -754,7 +754,15 @@ static int st7701_dsi_probe(struct mipi_dsi_device *dsi)
 	st7701->dsi = dsi;
 	st7701->desc = desc;
 
-	return mipi_dsi_attach(dsi);
+	ret = mipi_dsi_attach(dsi);
+	if (ret)
+		goto err_attach;
+
+	return 0;
+
+err_attach:
+	drm_panel_remove(&st7701->panel);
+	return ret;
 }
 
 static void st7701_dsi_remove(struct mipi_dsi_device *dsi)