drivers/video/fbdev/sm501fb.c: avoid world-writable sysfs files.
drivers/video/fbdev/sm501fb.c: avoid world-writable sysfs files.

In line with practice for module parameters, we're adding a build-time
check that sysfs files aren't world-writable.

Cc: Vincent Sanders <9b50d1f90e62bf2b07ce4a2c12ae735ccb4c3d05@simtec.co.uk>
Cc: Ben Dooks <73675debcd8a436be48ec22211dcf44fe0df0a64@simtec.co.uk>
Signed-off-by: Rusty Russell <df9728c9e5104131c08c7adb03af425394842596@rustcorp.com.au>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs