staging: olpc_dcon: revert strtoul change

On Fri, 4 Feb 2011 15:44:43 -0800

From: Andres Salomon <dilinger@queued.net>

The s/simple_strtoul/strict_strtoul/ from commit e107e6eb added a build
warning, as well as an oops.  This reverts that change.

Signed-off-by: Andres Salomon <dilinger@queued.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>