kselftest/arm64: mte: user_mem: add more test types

To expand the test coverage for MTE tags in userspace memory,
also perform the test with `write`, `readv` and `writev` syscalls.

Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220209152240.52788-6-joey.gouly@arm.com


Signed-off-by: Will Deacon <will@kernel.org>