Revert "Bluetooth: hci_sync: Fix overwriting request callback"

This reverts commit da77c1d3 which is
commit 2615fd9a upstream.

It is reported to cause regressions in the 6.1.y tree, so revert it for
now.

Link: https://lore.kernel.org/all/CADRbXaDqx6S+7tzdDPPEpRu9eDLrHQkqoWTTGfKJSRxY=hT5MQ@mail.gmail.com/


Reported-by: Jeremy Lainé <jeremy.laine@m4x.org>
Cc: Salvatore Bonaccorso <carnil@debian.org>
Cc: Mike <user.service2016@gmail.com>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: Paul Menzel <pmenzel@molgen.mpg.de>
Cc: Pauli Virtanen <pav@iki.fi>
Cc: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Cc: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>