staging: wilc1000: replace WILC_ErrNo by int type

This patch replaces WILC_ErrNo with int type.
WILC_ErrNo typedef is also removed.

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