Bugfix:  voltha-go-builder Docker image build must use new path to golint

Change-Id: I5ac6bcfdfda107d05b0287ad66a47622a7df78f1
diff --git a/envoy/go/golang-builder/Dockerfile b/envoy/go/golang-builder/Dockerfile
index 0b6648c..ae5ab59 100644
--- a/envoy/go/golang-builder/Dockerfile
+++ b/envoy/go/golang-builder/Dockerfile
@@ -10,7 +10,7 @@
 
 RUN go get github.com/pwaller/goupx \
 	&& go get golang.org/x/tools/cmd/cover \
-    && go get -u github.com/golang/lint/golint \
+    && go get -u golang.org/x/lint/golint \
     && go get github.com/kisielk/errcheck \
     && go get github.com/cespare/prettybench \
     && go get github.com/uber/go-torch