staging: wilc1000: remove 'ret' variable in handle_key()

Remove the use of unnecessary 'ret' variable and use existing 'result'
variable to hold the status. Also changed type of 'result' from s32 to
int to confirm with the function return type.

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