can: janz-ican3: fix type mismatch in assignment

return type of wait_for_completion_timeout is unsigned long not int, this patch
removes the type mismatch by moving the call into the condition.

Signed-off-by: Nicholas Mc Guire <der.herr@hofr.at>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>