Merge pull request #113229 from BenTheElder/more-shell-tidy

more shellcheck cleanups

hack/lib/util.sh

@@ -656,6 +656,7 @@ function kube::util::join {
 #  CFSSL_BIN: The path of the installed cfssl binary
 #  CFSSLJSON_BIN: The path of the installed cfssljson binary
 #
+# shellcheck disable=SC2120 # optional parameters
 function kube::util::ensure-cfssl {
   if command -v cfssl &>/dev/null && command -v cfssljson &>/dev/null; then
     CFSSL_BIN=$(command -v cfssl)

hack/local-up-cluster.sh

@@ -186,7 +186,7 @@ do
     esac
 done
 
-if [ "x${GO_OUT}" == "x" ]; then
+if [ -z "${GO_OUT}" ]; then
     make -C "${KUBE_ROOT}" WHAT="cmd/kubectl cmd/kube-apiserver cmd/kube-controller-manager cmd/cloud-controller-manager cmd/kubelet cmd/kube-proxy cmd/kube-scheduler"
 else
     echo "skipped the build."