staging: wilc1000: rename pJoinParams in CfgScanResult function

This patch renames pJoinParams to join_params that is
fourth argument of CfgScanResult function to avoid camelcase.

Signed-off-by: Leo Kim <leo.kim@atmel.com>
Signed-off-by: Glen Lee <glen.lee@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>