staging: wilc1000: rename variables using camelCase in add_key()

This is a cleanup patch to avoid using camelCase for variable
names.
Changes fix "Avoid camelCase" issue reported by checkpatch.pl script.

Signed-off-by: Ajay Singh <ajay.kathat@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>