greybus: connection: log cport-enable error messages

Log failures to disable a host cport, and include the connection name in
cport enable/disable error messages.

Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>