selftests: arm64: Remove extraneous register setting code

For some reason the SVE ptrace test code starts off by setting values in
some of the SVE vector registers in the parent process which it then never
interacts with when verifying the ptrace interfaces. This is not especially
relevant to what's being tested and somewhat confusing when reading the
code so let's remove it.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20210913125505.52619-4-broonie@kernel.org


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