Input: cyttsp4 - remove unnecessary work pending test

Remove unnecessary work pending test before calling schedule_work().  It
has been tested in queue_work_on() already.

Signed-off-by: Xie XiuQi <xiexiuqi@huawei.com>
Reviewed-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>