ci: forward the exit code from update-repos

If update-repos fails with status 128 then that means it failed to fetch
the remote repositories.  This should result in a warning not a failure
but flock was just returning status 1.

Save the exit code and if it returns 128 continue but exit with it
later, so the lockfile generation still occurs but the job doesn't fail.

Also, only call the update-repos script if KAS_REPO_REF_DIR has been set.

Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Jon Mason <jon.mason@arm.com>

.gitlab-ci.yml

@@ -96,7 +96,13 @@ update-repos:
     exit_codes: 128
   script:
     - |
-      flock --verbose --timeout 60 $KAS_REPO_REF_DIR ./ci/update-repos
+      exit_code=0
+      if [ -n "$KAS_REPO_REF_DIR" ]; then
+        flock --verbose --timeout 60 $KAS_REPO_REF_DIR --command ./ci/update-repos || exit_code=$?
+        # Exit now if that failed, unless the status was 128 (fetch failed)
+        test $exit_code != 0 -a $exit_code != 128 && exit 1
+      fi
+
       # Only generate if doesn't already exist, to allow feature branches to drop one in.
       if test -f lockfile.yml; then
         echo Using existing lockfile.yml
@@ -104,6 +110,7 @@ update-repos:
         # Be sure that this is the complete list of layers being fetched
         kas dump --lock --update ci/qemuarm64.yml:ci/meta-openembedded.yml:ci/clang.yml:ci/meta-virtualization.yml | tee lockfile.yml
       fi
+      exit $exit_code
   artifacts:
     name: "lockfile"
     paths: