Change to GOPATH before go get

So it won't touch go.mod

Signed-off-by: Shengjing Zhu <zhsj@debian.org>

script/setup/install-cni-windows

@@ -21,6 +21,7 @@ WINCNI_BIN_DIR="${DESTDIR}/cni"
 WINCNI_PKG=github.com/Microsoft/windows-container-networking
 WINCNI_VERSION=aa10a0b31e9f72937063436454def1760b858ee2
 
+cd "$GOPATH"
 go get -d "${WINCNI_PKG}/..."
 cd "${GOPATH}/src/${WINCNI_PKG}"
 git checkout "${WINCNI_VERSION}"

script/setup/install-critools

@@ -20,6 +20,7 @@
 #
 set -eu -o pipefail
 
+cd "$GOPATH"
 go get -u github.com/onsi/ginkgo/ginkgo
 CRITEST_COMMIT=0f5f734a7e1da0979915c6e7d5b6641bd9dc2627
 go get -d github.com/kubernetes-sigs/cri-tools/...

script/setup/install-dev-tools

@@ -20,6 +20,9 @@
 #
 set -eu -o pipefail
 
+# change to tmp dir, otherwise `go get` will change go.mod
+cd "$GOPATH"
+
 # install the `protobuild` binary in $GOPATH/bin; requires module-aware install
 # to pin dependencies
 GO111MODULE=on go get github.com/stevvooe/protobuild