Bluetooth: check L2CAP info_rsp ident and state

Information requests/responses are unbound to L2CAP channel. Patch
fixes issue arising when two devices connects at the same time to
each other. This way we do not process out of the context messages.
We are safe dropping info_rsp since info_timer is left running.

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>