staging: vt6656: Remove return statement of iwctl_giwrange

The function iwctl_giwrange 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>

diff --cc drivers/staging/vt6656/iwctl.c
Simple merge

diff --cc drivers/staging/vt6656/iwctl.h
Simple merge

diff --cc drivers/staging/vt6656/main_usb.c
Simple merge