staging: wilc1000: use void return for wilc_hif_pack_sta_param()

Change the return type from u32 to void for wilc_hif_pack_sta_param() as
its value is not used. Also remove the use of extra pointer as it's not
required now.

Signed-off-by: Ajay Singh <ajay.kathat@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>