Fix: draid autopkgtests fail on s390x architecture (Endianness Issue)

[pranavkaruvally]

Motivation and Context

Creating a draid1 pool was resulting in the following error:

cannot create 'pool-smoke-201219': invalid argument for this pool operation

This patch fixes this issue. Closes #16261

Description

The ioctl call to create the pool was returning -1 with errno EINVAL. Inside the module code, inside vdev_draid.c, verify_perms is calling fletcher_4_native_varsize. This in turn calls fletcher_4_scalar_native. So, implemented a fletcher_4_byteswap_varsize which makes use of the fletcher_4_scalar_byteswap in Big endian machines.

How Has This Been Tested?

• Used draid verify to verify the generated draid maps
• Created a storage pool on s390x, exported it, imported it on a little endian machine, and verified the checksums of the files within the storage pool. Checked with 10 vdisks of 10 GB each and 10 files of 8 GB each

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Performance enhancement (non-breaking change which improves efficiency)
• Code cleanup (non-breaking change which makes code smaller or more readable)
• Quality assurance (non-breaking change which makes the code more robust against bugs)
• Breaking change (fix or feature that would cause existing functionality to change)
• Library ABI change (libzfs, libzfs_core, libnvpair, libuutil and libzfsbootenv)
• Documentation (a change to man pages or other documentation)

Checklist:

• My code follows the OpenZFS code style requirements.
• I have updated the documentation accordingly.
• I have read the contributing document.
• I have added tests to cover my changes.
• I have run the ZFS Test Suite with this change applied.
• All commit messages are properly formatted and contain Signed-off-by.

[behlendorf]

One last change. To resolve the checkstyle failure you'll need to download the updated ABI files from the PR artifacts here, https://github.com/openzfs/zfs/actions/runs/24707802425?pr=18445. Then add the updated lib/libzfs/libzfs.abi file from that tarball to this PR.

[behlendorf]

It looks like we have a few additional recent ABI changes which didn't get flagged initially. Those should have been part of their original commits, but we can fix it up here. Thanks.