There was a detected user error in the code where racing insertions of
k_delayed_work items into different queues would be detected and
flagged as an error (honestly I don't see much value there -- Zephyr
doesn't as a general rule protect against errors like this, and
work_q's are inherently kernel things that don't require
userspace-style checking).
This got broken with spinlockification, where each work_q object got
its own lock, so the single lock wouldn't protect against the other
insert function any more. As it happens, that was needless. The core
synchronization on a work_q is in the internal k_queue object anyway
-- the lock in this file was only ever used for (very fast,
noncontending) delayed work insertion. So go back to a global lock to
preserve the original behavior.
Fixes#14104
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>