Licensing: skip modules with fewer subdirs than mods

This came up when updating go-oidc. After updating go-oidc (with its
dependency tree), cloud.google.com/go was no longer used as a package
import, but still listed in the module dependency graph; as a result,
"go mod vendor" no longer pulled in cloud.google.com/go itself, but
update-vendor-licenses.sh still wanted a license file for it since it
appeared in the list of modules.

This scenario is already supposed to be handled: when a module doesn't
contain any *files* as first-level content, if the number of
subdirectories it contains *equals* the number of submodules it
contains (excluding itself), the module is skipped. This fails for
cloud.google.com/go because several submodules are included in the
module dependency graph but aren't actually used, and therefore not
vendored.

Updating the test to check that the number of subdirectories is less
than or equal to the number of expected submodules fixes this.

The correct fix would be to process the submodules first, keeping a
note of which ones really have content, then check that the top-level
module only contains subdirectories corresponding to those modules;
but it's not clear to me that this is worth the effort (especially in
a shell script).

Signed-off-by: Stephen Kitt <skitt@redhat.com>

hack/update-vendor-licenses.sh

@@ -201,8 +201,8 @@ for PACKAGE in ${modules}; do
 
   # if there are no files vendored under this package...
   if [[ -z "$(find "${DEPS_DIR}/${PACKAGE}" -mindepth 1 -maxdepth 1 -type f)" ]]; then
-    # and we have the same number of submodules as subdirectories...
-    if [[ "$(find "${DEPS_DIR}/${PACKAGE}/" -mindepth 1 -maxdepth 1 -type d | wc -l)" -eq "$(echo "${modules}" | grep -cE "^${PACKAGE}/")" ]]; then
+    # and we have at least the same number of submodules as subdirectories...
+    if [[ "$(find "${DEPS_DIR}/${PACKAGE}/" -mindepth 1 -maxdepth 1 -type d | wc -l)" -le "$(echo "${modules}" | grep -cE "^${PACKAGE}/")" ]]; then
       echo "Only submodules of ${PACKAGE} are vendored, skipping" >&2
       continue
     fi