Staging: olpc_dcon: more big endian conformity

Using an int which is casted to unsigned char as inbuf is messy.
The code won't work on big endian systems.  The patch should fix
this.

Signed-off-by: Jens Frederich <jfrederich@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>