Remove test for AES-256-XTS with 32-byte master key
Remove test for AES-256-XTS with 32-byte master key

The v5.16 kernel intentionally reduced the minimum master key size for
AES-256-XTS from 64 bytes to 32 bytes, provided that a v2 encryption
policy is used.  See https://git.kernel.org/linus/7f595d6a6cdc3368

Therefore, remove the fscryptctl test which verified that 32-byte master
keys were not allowed with AES-256-XTS.

Fixes #26

google/fscryptctl,google/fscryptctl