Bluetooth: debug: Correct the PSM printing

Earlier we were printing chan->psm before assigning any value.

Signed-off-by: Syam Sidhardhan <s.syam@samsung.com>
Acked-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>