odp-util: Make checks for exact or wildcard masks more precise.

odp-util: Make checks for exact or wildcard masks more precise.

Checking whether an ODP mask is all-0s or all-1s is a little more
complicated than one might expect because the structures sometimes have
trailing padding.  The function odp_mask_is_exact() was fairly careful
about this, but odp_mask_attr_is_wildcard() didn't take padding into
consideration at all, which caused test failures on Travis and on some
machines because of uninitialized padding.

This commit fixes the problem by unifying the two different functions so
that both of them are careful about checking only significant bytes.  It
also adds support for the ct_orig_tuples for IPv4 and IPv6, which also
have trailing padding but weren't special cased before.

Signed-off-by: Ben Pfaff <blp@ovn.org>
Acked-by: Andy Zhou <azhou@ovn.org>