Revert "Bluetooth: hci_core: Fix sleeping function called from invalid context"

This reverts commit 4d94f055 which has
problems (see [1]) and is no longer needed since 581dd2dc
("Bluetooth: hci_event: Fix using rcu_read_(un)lock while iterating")
has reworked the code where the original bug has been found.

[1] Link: https://lore.kernel.org/linux-bluetooth/877c55ci1r.wl-tiwai@suse.de/T/#t


Fixes: 4d94f055 ("Bluetooth: hci_core: Fix sleeping function called from invalid context")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>