staging: wilc1000: simplify 'memset' of 2D array

This patch simplifies the 'memset' done on a static 2D array.

Signed-off-by: Hari Prasath Gujulan Elango <hgujulan@visteon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>