kselftest: arm64: Fix exit code of sve-ptrace

We track if sve-ptrace encountered a failure in a variable but don't
actually use that value when we exit the program, do so.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20210309190304.39169-1-broonie@kernel.org


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