bluetooth: Properly clone LSM attributes to newly created child connections

The Bluetooth stack has internal connection handlers for all of the various
Bluetooth protocols, and unfortunately, they are currently lacking the LSM
hooks found in the core network stack's connection handlers.  I say
unfortunately, because this can cause problems for users who have have an
LSM enabled and are using certain Bluetooth devices.  See one problem
report below:

 * http://bugzilla.redhat.com/show_bug.cgi?id=741703



In order to keep things simple at this point in time, this patch fixes the
problem by cloning the parent socket's LSM attributes to the newly created
child socket.  If we decide we need a more elaborate LSM marking mechanism
for Bluetooth (I somewhat doubt this) we can always revisit this decision
in the future.

Reported-by: James M. Cape <jcape@ignore-your.tv>
Signed-off-by: Paul Moore <pmoore@redhat.com>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: David S. Miller <davem@davemloft.net>