kselftest/arm64: Log unexpected asynchronous MTE faults

Help people figure out problems by printing a diagnostic when we get an
unexpected asynchronous fault.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Link: https://lore.kernel.org/r/20220419103243.24774-3-broonie@kernel.org


Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>