Bluetooth: Fix LE conn creation

This patch prevents a crash when remote host tries to create a LE
link which already exists. i.e.: call l2test twice passing the
same parameters.

Signed-off-by: Anderson Briglia <anderson.briglia@openbossa.org>
Signed-off-by: Ville Tervo <ville.tervo@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>