Fix building with GOFLAGS=-v

With go1.15 running go version with "-v" fails, and we should support
it.

Author: odinuge

hack/lib/golang.sh

@@ -465,7 +465,7 @@ EOF
   fi
 
   local go_version
-  IFS=" " read -ra go_version <<< "$(go version)"
+  IFS=" " read -ra go_version <<< "$(GOFLAGS='' go version)"
   local minimum_go_version
   minimum_go_version=go1.15.0
   if [[ "${minimum_go_version}" != $(echo -e "${minimum_go_version}\n${go_version[2]}" | sort -s -t. -k 1,1 -k 2,2n -k 3,3n | head -n1) && "${go_version[2]}" != "devel" ]]; then
@@ -777,7 +777,7 @@ kube::golang::build_binaries() {
   (
     # Check for `go` binary and set ${GOPATH}.
     kube::golang::setup_env
-    V=2 kube::log::info "Go version: $(go version)"
+    V=2 kube::log::info "Go version: $(GOFLAGS='' go version)"
 
     local host_platform
     host_platform=$(kube::golang::host_platform)