Bluetooth: Fix cancel_delayed_work_sync usage with locks

The cancel_delayed_work_sync function should not be used if we hold any
locks. Luckily all places where this is the case it is also safe to use
the non-sync version.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>