Shiftfs module does not compile on kernel versions 5.12+

Once again; this time there seem to be many ABI changes…

For more information, take a look at my bugreport on GitHub:

@brauner @stgraber

I couldn’t seem to find a newer ubuntu kernel repo than 5.11.

The problem is now fixed, thx to @brauner , and a new version of my dkms scripts is also available for kernel version 5.13: