staging: wilc1000: Handle_SetMulticastFilter(): fixes right shifting more than type allows

This patch fixes the warning reported by smatch.
 - Handle_SetMulticastFilter() warn: right shifting more than type allows

That is unnecessary action of boolean type. just assign 0.

Signed-off-by: Leo Kim <leo.kim@atmel.com>
Signed-off-by: Glen Lee <glen.lee@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>