aiaiai: don't allow arbitrary validator command

aiaiai: don't allow arbitrary validator command

Since aiaiai-email-test-patchset is the only validator that makes sense,
and we should extend it if new features are desired, we don't need to
support multiple validators, as this is clunky, and difficult to
configure for the user. Now that the configuration file supports all the
options from the aiaiai-email-test-patchset, we can just directly call
it instead of having to use a passed in parameter.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>