staging: wfx: fix swapped arguments in memset call

The memset appears to have the 2nd and 3rd arguments in the wrong
order, fix this by swapping these around into the correct order.

Addresses-Coverity: ("Memset fill truncated")
Fixes: 4f8b7fab ("staging: wfx: allow to send commands to chip")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20191009094602.19663-1-colin.king@canonical.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>