Input: exc3000 - fix return value check of wait_for_completion_timeout

Input: exc3000 - fix return value check of wait_for_completion_timeout

wait_for_completion_timeout() returns unsigned long not int.
It returns 0 if timed out, and positive if completed.
The check for <= 0 is ambiguous and should be == 0 here
indicating timeout which is the only error case.

Fixes: 8bc7d0f5f7d4 ("Input: exc3000 - factor out vendor data request")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Link: https://lore.kernel.org/r/20220411105828.22140-1-linmq006@gmail.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>