staging: vt6656: iwctl.c: Remove return statement of iwctl_giwessid

This function will always return 0, and this data is not used by who
calls this function.

Signed-off-by: Marcos Paulo de Souza <marcos.mage@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>