test.bash: use "go vet" instead of "go tool vet"
test.bash: use "go vet" instead of "go tool vet"

"go vet" automatically skips the vendor directory.
"go tool vet" does not, and it will complain about a lot
of things in there.

rfjakob/gocryptfs,rfjakob/gocryptfs,rfjakob/gocryptfs,rfjakob/gocryptfs