BACKPORT: io_uring: add io_local_work_pending()

In preparation for adding a new llist of tw to retry due to hitting the
tw limit, add a helper io_local_work_pending(). This function returns
true if there is any local tw pending. For now it only checks
ctx->work_llist.

Bug: 297114355
(cherry picked from commit 40cfe553)
[akailash@: Fix merge conflict in io_has_work function ]
Signed-off-by: David Wei <dw@davidwei.uk>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/20241120221452.3762588-2-dw@davidwei.uk


Signed-off-by: Akilesh Kailash <akailash@google.com>
Change-Id: I701e7df01072051be1c2f0967f056cc8a2923e99