device_create() is race-prone, so use the race-free
device_create_drvdata() instead as device_create() is going away.

Cc: Ben Collins <ben.collins@ubuntu.com>
Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>