signal: kill JOBCTL_TASK_WORK

stable inclusion
from stable-v5.10.162
commit c91ab04781f9e46c1a2143bd1ba8fc1f1aff6ebc
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I7P7OH

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=c91ab04781f9e46c1a2143bd1ba8fc1f1aff6ebc



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[ Upstream commit 98b89b64 ]

It's no longer used, get rid of it.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: sanglipeng <sanglipeng1@jd.com>