hci_sock_cleanup() always returns 0 and its return value isn't used
anywhere in the code.

Compile-tested with 'make allyesconfig && make net/bluetooth/bluetooth.ko'
Signed-off-by: NTobias Klauser <tklauser@distanz.ch>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>