vet: put a notice in main that this version of vet is not the place to update
vet: put a notice in main that this version of vet is not the place to update

Change-Id: I295d1e902626a3f5edd09a3b594a2059530ca821
Reviewed-on: https://go-review.googlesource.com/14820
Reviewed-by: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>

jdhenke/tools,golang/tools,golang/tools,cmars/tools,magiccao/tools,syreclabs/go-tools,syreclabs/go-tools,syreclabs/go-tools,golang/tools,jdhenke/tools,magiccao/tools,magiccao/tools,golang/tools,syreclabs/go-tools,jdhenke/tools,magiccao/tools,cmars/tools,cmars/tools,cmars/tools,syreclabs/go-tools,golang/tools,syreclabs/go-tools,jdhenke/tools