If BREDR L2CAP chan is deleted and this chan is the channel through
which High Speed traffic is routed to AMP then zero pointer to
the chan in amp_mgr to prevent accessing it.
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com> Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>