Revert "Rewrite go_install_from_commit to handle pkgs that aren't in HEAD"

hack/lib/util.sh

@@ -476,15 +476,10 @@ kube::util::go_install_from_commit() {
 
   kube::util::ensure-temp-dir
   mkdir -p "${KUBE_TEMP}/go/src"
-  # TODO(spiffxp): remove this brittle workaround for go getting a package that doesn't exist at HEAD
-  repo=$(echo ${pkg} | cut -d/ -f1-3)
-  git clone "https://${repo}" "${KUBE_TEMP}/go/src/${repo}"
-  # GOPATH="${KUBE_TEMP}/go" go get -d -u "${pkg}"
+  GOPATH="${KUBE_TEMP}/go" go get -d -u "${pkg}"
   (
-    cd "${KUBE_TEMP}/go/src/${repo}"
-    git fetch # TODO(spiffxp): workaround
+    cd "${KUBE_TEMP}/go/src/${pkg}"
     git checkout -q "${commit}"
-    GOPATH="${KUBE_TEMP}/go" go get -d "${pkg}" #TODO(spiffxp): workaround
     GOPATH="${KUBE_TEMP}/go" go install "${pkg}"
   )
   PATH="${KUBE_TEMP}/go/bin:${PATH}"