Normalize route destination before checking for MPATH conflicts.
Normalize route destination before checking for MPATH conflicts.

This makes rt_mpath_conflict() work as expected when adding routes
with the same destination and the same netmask.

With and ok claudio@

orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars