user can configurare scrub cycle for a region or a memory device via
sysfs interface. Currently, these interfaces have not enough description
for the return value. So adding return value description to these
interfaces.
Suggested-by: Alison Schofield <alison.schofield@xxxxxxxxx>
Signed-off-by: Shiju Jose <shiju.jose@xxxxxxxxxx>
Signed-off-by: Li Ming <ming.li@xxxxxxxxxxxx>