- Provide bce_get_counter() to return counters that are not collected,
  but taken from hardware.
- Mechanically convert to if_inc_counter() the rest of counters.
- While here fix 3 instances of the same bug, when error counter was ++
  in one place and then assigned in other place, losing the increment.
  Achieve that storing soft errors counters in softc.


git-svn-id: svn+ssh://svn.freebsd.org/base/head@272096 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f