slimbus: qcom-ngd: Add error handling in of_qcom_slim_ngd_register

No error handling is performed when platform_device_add()
return fails. Refer to the error handling of driver_set_override(),
add error handling for platform_device_add().

Fixes: 917809e2280b ("slimbus: ngd: Add qcom SLIMBus NGD driver")
Reviewed-by: Neil Armstrong <[e-mail]>
Signed-off-by: Lin Yujun <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/slimbus/qcom-ngd-ctrl.c

···
 		ngd->pdev->dev.of_node = node;
 		ctrl->ngd = ngd;
 
-		platform_device_add(ngd->pdev);
+		ret = platform_device_add(ngd->pdev);
+		if (ret) {
+			platform_device_put(ngd->pdev);
+			kfree(ngd);
+			of_node_put(node);
+			return ret;
+		}
 		ngd->base = ctrl->base + ngd->id * data->offset +
 					(ngd->id - 1) * data->size;