staging/comedi/das16: Make timer initialization unconditional

With timer initialization made unconditional, there is no reason to
make del_timer_sync() calls conditionally, there by removing the test
of the .data field.

Cc: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: devel@driverdev.osuosl.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>