staging: wilc1000: fix line over 80 char in handle_cfg_param()

Fix 'line over 80 char' issues found by checkpatch.pl script in
handle_cfg_param(). Rename variables and used temporary variables
to fix the line over 80 characters issue.
Signed-off-by: Ajay Singh <ajay.kathat@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>