drm/komeda: Add check for komeda_get_layer_fourcc_list()

Add check for the return value of komeda_get_layer_fourcc_list()
to catch the potential exception.

Fixes: 5d51f6c ("drm/komeda: Add writeback support")
Cc: stable@vger.kernel.org
Signed-off-by: Haoxiang Li <haoxiang_li2024@163.com>
Acked-by: Liviu Dudau <liviu.dudau@arm.com>
Link: https://lore.kernel.org/r/20241219090256.146424-1-haoxiang_li2024@163.com
Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>

Author: Haoxiang Li

drivers/gpu/drm/arm/display/komeda/komeda_wb_connector.c

@@ -160,6 +160,10 @@ static int komeda_wb_connector_add(struct komeda_kms_dev *kms,
 	formats = komeda_get_layer_fourcc_list(&mdev->fmt_tbl,
 					       kwb_conn->wb_layer->layer_type,
 					       &n_formats);
+	if (!formats) {
+		kfree(kwb_conn);
+		return -ENOMEM;
+	}
 
 	err = drm_writeback_connector_init(&kms->base, wb_conn,
 					   &komeda_wb_connector_funcs,