Staging: wilc1000: Prefer eth_broadcast_addr over memset()

This patch is to the host_interface.c that fixes up following
warning by checkpatch:

-prefer eth_broadcast_addr() over memset()

Signed-off-by: Punit Vara <punitvara@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>