upstream kernels only have network_v8 unfortunately the tcp tests were
only being run against kernels that had network (which is v7). Kernels
that support both (Ubuntu) would be tested against v8, so v8 has been
tested but pure upstream kernels were failing to be tested correctly.

This patch will only make sure one of the supported versions are
tested. This is determined by the parser which prefers v8. In the
future the tests need to be extended to run the tests against all
kernel supported versions.

Signed-off-by: John Johansen <john.johansen@canonical.com>