ml: Return after BreakLoop() in worker process of speech recognizer.

If SodaRecognizerImpl::Create() fails, the intention is to break the
message loop AND return. Add the missing return statement.

BUG=chromium:1252229, chromium:1220271
TEST=Verified locally that code after BreakLoop() can still run,
TEST=so a return is needed.

Change-Id: Ic480ccb24702b139bfb2930e6c405a746ba05c5f
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform2/+/3177453
Commit-Queue: Amanda Deacon <amandadeacon@chromium.org>
Commit-Queue: Honglin Yu <honglinyu@chromium.org>
Tested-by: Amanda Deacon <amandadeacon@chromium.org>
Auto-Submit: Amanda Deacon <amandadeacon@chromium.org>
Reviewed-by: Honglin Yu <honglinyu@chromium.org>
diff --git a/ml/machine_learning_service_impl.cc b/ml/machine_learning_service_impl.cc
index ca3b016..230791d 100644
--- a/ml/machine_learning_service_impl.cc
+++ b/ml/machine_learning_service_impl.cc
@@ -557,6 +557,7 @@
     std::move(callback).Run(LoadModelResult::LOAD_MODEL_ERROR);
     request_metrics.RecordRequestEvent(LoadModelResult::LOAD_MODEL_ERROR);
     brillo::MessageLoop::current()->BreakLoop();
+    return;
   }
 
   std::move(callback).Run(LoadModelResult::OK);