vet: fix documentation about recursive scanning
vet: fix documentation about recursive scanning

It used to do packages only when run by the go tool, but it was
fixed a while back to handle packages properly when doing a
directory walk. Remove the incorrect information from the
documentation.

Change-Id: I961340bb84e48474c94ee03bf88f9136492c0226
Reviewed-on: https://go-review.googlesource.com/7642
Reviewed-by: Andrew Gerrand <395a7d33bec8475c9b83b7d440f141bcbd994aa5@golang.org>

matryer/tools,cw2018/tools,nicot/tools,jdhenke/tools,cmars/tools,argandas/tools,springning/tools,argandas/tools,golang/tools,cw2018/tools,glasser/golang-tools,magiccao/tools,argandas/tools,dmitris/tools,glasser/golang-tools,golang/tools,dmitris/tools,josharian/tools,syreclabs/go-tools,nicot/tools,magiccao/tools,matryer/tools,cmars/tools,syreclabs/go-tools,josharian/tools,syreclabs/go-tools,syreclabs/go-tools,runcom/tools,glasser/golang-tools,runcom/tools,sshetty10/tools,jdhenke/tools,golang/tools,sshetty10/tools,nicot/tools,jdhenke/tools,josharian/tools,syreclabs/go-tools,argandas/tools,syreclabs/go-tools,matryer/tools,josharian/tools,golang/tools,cmars/tools,nicot/tools,cmars/tools,dmitris/tools,springning/tools,dmitris/tools,springning/tools,matryer/tools,cw2018/tools,magiccao/tools,jdhenke/tools,magiccao/tools,cw2018/tools,glasser/golang-tools,sshetty10/tools,golang/tools,sshetty10/tools,runcom/tools,springning/tools,runcom/tools