Bluetooth: Fix RFCOMM bind fail for L2CAP sock

L2CAP socket bind checks its bdaddr type but RFCOMM kernel thread
does not assign proper bdaddr type for L2CAP sock. This can cause
that RFCOMM failure.

Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>