packaging: Fix clh build from source fall-back

If we fail to download the clh binary, we fall-back to build from source.
Unfortunately, `pull_clh_released_binary()` leaves a `cloud_hypervisor`
directory behind, which causes `build_clh_from_source()` not to clone
the git repo:

    [ -d "${repo_dir}" ] || git clone "${cloud_hypervisor_repo}"

When building from a kata-containers git repo, the subsequent calls
to `git` in this function thus apply to the kata-containers repo and
eventually fail, e.g.:

+ git checkout v23.0
error: pathspec 'v23.0' did not match any file(s) known to git

It doesn't quite make sense actually to keep an existing directory the
content of which is arbitrary when we want to it to contain a specific
version of clh. Just remove it instead.

Fixes: #4151

Signed-off-by: Greg Kurz <groug@kaod.org>

tools/packaging/static-build/cloud-hypervisor/build-static-clh.sh

@@ -55,7 +55,8 @@ build_clh_from_source() {
     info "Build ${cloud_hypervisor_repo} version: ${cloud_hypervisor_version}"
     repo_dir=$(basename "${cloud_hypervisor_repo}")
     repo_dir="${repo_dir//.git}"
-    [ -d "${repo_dir}" ] || git clone "${cloud_hypervisor_repo}"
+    rm -rf "${repo_dir}"
+    git clone "${cloud_hypervisor_repo}"
     pushd "${repo_dir}"
 
     if [ -n "${cloud_hypervisor_pr}" ]; then