drm/panel: innolux-p079zca: Delete panel on attach() failure

If we fail to attach (e.g., because 1 of 2 dual-DSI controllers aren't
ready), we leave a dangling drm_panel reference to freed memory. Clean
that up on failure.

This problem exists since the driver's introduction, but is especially
relevant after refactored for dual-DSI variants.

Fixes: 14c8f2e9 ("drm/panel: add Innolux P079ZCA panel driver")
Fixes: 7ad4e463 ("drm/panel: p079zca: Refactor panel driver to support multiple panels")
Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210923173336.2.I9023cf8811a3abf4964ed84eb681721d8bb489d6@changeid

drivers/gpu/drm/panel/panel-innolux-p079zca.c

@@ -484,6 +484,7 @@ static void innolux_panel_del(struct innolux_panel *innolux)
 static int innolux_panel_probe(struct mipi_dsi_device *dsi)
 {
 	const struct panel_desc *desc;
+	struct innolux_panel *innolux;
 	int err;
 
 	desc = of_device_get_match_data(&dsi->dev);
@@ -495,7 +496,14 @@ static int innolux_panel_probe(struct mipi_dsi_device *dsi)
 	if (err < 0)
 		return err;
 
-	return mipi_dsi_attach(dsi);
+	err = mipi_dsi_attach(dsi);
+	if (err < 0) {
+		innolux = mipi_dsi_get_drvdata(dsi);
+		innolux_panel_del(innolux);
+		return err;
+	}
+
+	return 0;
 }
 
 static int innolux_panel_remove(struct mipi_dsi_device *dsi)