fix: adding crc32c for ext3

[johannbg]

Noticed that ext3 is still being used in the wild so let's add it to the crc32c list
so downstream does not have to carry a patch for it.

This pull request changes...

Changes

Checklist

• I have tested it locally
• I have reviewed and updated any documentation if relevant
• I am providing new code and test(s) for it

Fixes #

[marcosfrm]

Btrfs since 5.5 supports additional hash functions:

# modinfo btrfs
filename:       /lib/modules/5.12.1-arch1-1/kernel/fs/btrfs/btrfs.ko.xz
softdep:        pre: blake2b-256
softdep:        pre: sha256
softdep:        pre: xxhash64
softdep:        pre: crc32c

But the softdeps are there since 5.5

https://github.com/torvalds/linux/blob/v5.5/fs/btrfs/super.c#L2467

hence no need to specify they here right?

[haraldh]

hence no need to specify they here right?

right