bluetooth: replace deprecated RW_LOCK_UNLOCKED macros

The older RW_LOCK_UNLOCKED macros defeat lockdep state tracing so
replace them with the newer __RW_LOCK_UNLOCKED macros.

Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>