bonding: set xfrm feature flags more sanely

We can remove one of the ifdef blocks here, and instead of setting both
the xfrm hw_features and features flags, then unsetting the feature
flags if not in AB, wait to set the features flags if we're actually in AB
mode.

Signed-off-by: Jarod Wilson <jarod@redhat.com>
Link: https://lore.kernel.org/r/20201205174003.578267-1-jarod@redhat.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>