There are just two of them (slow and thorough; quick is simply the
default). Avoid repeating them for as many times as there are tests.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>