Fix the return value check which testing the wrong variable
in thrustmaster_probe().

Fixes: c49c3363 ("HID: support for initialization of some Thrustmaster wheels")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>