These functions are defined in the mq-deadline.c file, but not called
elsewhere, so delete these unused functions.

block/mq-deadline.c:134:1: warning: unused function 'deadline_earlier_request'.
block/mq-deadline.c:148:1: warning: unused function 'deadline_latter_request'.
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=8803Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Link: https://lore.kernel.org/r/20240419025610.34298-1-jiapeng.chong@linux.alibaba.comSigned-off-by: Jens Axboe <axboe@kernel.dk>