Log Message:
editor/vigor: post-patch operation broke DragonFly

DragonFly replaced CIRCLEQ_* with TAILQ_* a few years back.  The
system sys/queue.h will not build editors/vigor.  The Makefile's
post-patch phase removed it's version of queue.h because it masked the
system sys/queue.h, which is exactly what is required for DragonFly.

Make this post-patch operation system specific: Do it only for
non-DragonFly platforms.