ACPICA: events/evxfregn: don't release the ContextMutex that was never acquired

ACPICA: events/evxfregn: don't release the ContextMutex that was never acquired

This bug was first introduced in c27f3d011b08, where the author of the
patch probably meant to do DeleteMutex instead of ReleaseMutex. The
mutex leak was noticed later on and fixed in e4dfe108371, but the bogus
MutexRelease line was never removed, so do it now.

Link: https://github.com/acpica/acpica/pull/982
Fixes: c27f3d011b08 ("ACPICA: Fix race in generic_serial_bus (I2C) and GPIO op_region parameter handling")
Signed-off-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
Link: https://patch.msgid.link/20241122082954.658356-1-d-tatianin@yandex-team.ru
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>