MFV r274272 and diff reduction with upstream.

Illumos issue:
    5244 zio pipeline callers should explicitly invoke next stage

Tested with:	ztest plus ZFS over GELI configuration
MFC after:	1 month
Merge remote-tracking branch 'freebsd/master' into hardened/current/master
Merge remote-tracking branch 'origin/hardened/current/master' into hardened/current/userlandenhanced