Revert "perf test 6: Fix missing kvm module load for s390"

This reverts commit 9a501cdb.

Which was upstream commit 53fe307d.

Ben Hutchings reports that this commit depends on new code added in
v4.18, and so is irrelevant on older kernels, and breaks the build.

Signed-off-by: Sasha Levin <sashal@kernel.org>