Input: synaptics-rmi4 - fix error return code in rmi_driver_probe()

Fix to return a negative error code from the input_register_device()
error handling case instead of 0, as done elsewhere in this function.
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Link: https://lore.kernel.org/r/20200428134948.78343-1-weiyongjun1@huawei.com
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/rmi4/rmi_driver.c

@@ -1210,7 +1210,8 @@ static int rmi_driver_probe(struct device *dev)
 	if (data->input) {
 		rmi_driver_set_input_name(rmi_dev, data->input);
 		if (!rmi_dev->xport->input) {
-			if (input_register_device(data->input)) {
+			retval = input_register_device(data->input);
+			if (retval) {
 				dev_err(dev, "%s: Failed to register input device.\n",
 					__func__);
 				goto err_destroy_functions;