HID: lenovo-tpkbd: fix leak if tpkbd_probe_tp fails

If tpkbd_probe_tp() bails out, the probe() function return an error,
but hid_hw_stop() is never called.

fixes:
https://bugzilla.redhat.com/show_bug.cgi?id=1003998



Cc: stable@vger.kernel.org
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>