Merge tag 'kvm-x86-selftests-6.6-fixes' of https://github.com/kvm-x86/linux into HEAD

KVM selftests fixes for 6.6:

 - Play nice with %llx when formatting guest printf and assert statements.

 - Clean up stale test metadata.

 - Zero-initialize structures in memslot perf test to workaround a suspected
   "may be used uninitialized" false positives from GCC.