BLUETOOTH: Fix unaligned access in hci_send_to_sock.

The "u16 *" derefs of skb->data need to be wrapped inside of
a get_unaligned().

Thanks to Gustavo Zacarias for the bug report.

Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Adrian Bunk <bunk@stusta.de>