Removed unused var.
Fixed error made in https://github.com/zikula/core/commit/8a5346d53624e3e6f0e2278b528b48ec88d102bd#diff-78d3efc381b4e86b333f5ec1ac95f747, closes #1254
Must be octal
Cast value back to octal.

The value stored in YAML 0777 will be converted to decimal which is 511,
so we need to convert it back.
Remove comment.
mkdir does not correctly set chmod
This conversion is no longer required.