Replace S_<PERMS> with octal values.

The conversion was done automatically with coccinelle. The semantic patches
and the scripts used to generate this commit log are available at
https://github.com/groeck/coccinelle-patches/hwmon/.

This patch does not introduce functional changes. It was verified by
compiling the old and new files and comparing text and data sizes.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>