cifs: dump channel info in DebugData

* show server&TCP states for extra channels
* mention if an interface has a channel connected to it

In this version three of the patch, fixed minor printk format
issue pointed out by the kbuild robot.
Reported-by: kbuild test robot <lkp@intel.com>

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>