x86/vmx: skip error-code delivery tests for #CP

Old Intel CPUs, which do not support control protection exception, do
not expect an error code for #CP, while new ones expect an error-code.

Intel SDM does not say that the delivery of an error-code for #CP is
conditional on anything, not even CPU support of CET. So it appears that
the correct testing is just to skip the error-code delivery test for
the #CP exception.

Signed-off-by: Nadav Amit <nadav.amit@gmail.com>
Message-Id: <20210609182945.36849-9-nadav.amit@gmail.com>