Input: hil_kbd - fix error return code in hil_dev_connect()

Return error code -EINVAL rather than '0' when the combo devices are not
supported.

Fixes: fa71c605 ("Input: combine hil_kbd and hil_ptr drivers")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Link: https://lore.kernel.org/r/20210515030053.6824-1-thunder.leizhen@huawei.comSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/keyboard/hil_kbd.c

@@ -512,6 +512,7 @@ static int hil_dev_connect(struct serio *serio, struct serio_driver *drv)
 		    HIL_IDD_NUM_AXES_PER_SET(*idd)) {
 			printk(KERN_INFO PREFIX
 				"combo devices are not supported.\n");
+			error = -EINVAL;
 			goto bail1;
 		}