staging: wilc1000: replace u8 with int.

This patch changes data type of variable i from u8 to int.
It is used as index of an array to print its content. It's better
to use as data type of int.

Signed-off-by: Chaehyun Lim <chaehyun.lim@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>