Now that we have govis, move everything to using govis.{Vis,Unvis} and
then remove the cvis build tags (because that code no longer exists).
Signed-off-by: Aleksa Sarai <asarai@suse.de>
The current Vis() and Unvis() are using the C implementation from
MTREE(8).
But that means that cgo is used, which is not always desired.
Signed-off-by: Vincent Batts <vbatts@hashbangbash.com>
