Inline queue size method in fixed executor builder

This commit inlines the queue size utility method in the fixed executor
builder as it was only used in one place.

core/src/main/java/org/elasticsearch/threadpool/FixedExecutorBuilder.java

@@ -105,7 +105,7 @@ ThreadPool.ExecutorHolder build(final FixedExecutorSettings settings, final Thre
         final ThreadFactory threadFactory = EsExecutors.daemonThreadFactory(EsExecutors.threadName(settings.nodeName, name()));
         Executor executor = EsExecutors.newFixed(name(), size, queueSize, threadFactory, threadContext);
         final ThreadPool.Info info =
-            new ThreadPool.Info(name(), ThreadPool.ThreadPoolType.FIXED, size, size, null, queueSizeValue(queueSize));
+            new ThreadPool.Info(name(), ThreadPool.ThreadPoolType.FIXED, size, size, null, queueSize < 0 ? null : new SizeValue(queueSize));
         return new ThreadPool.ExecutorHolder(executor, info);
     }
 
@@ -119,10 +119,6 @@ String formatInfo(ThreadPool.Info info) {
             info.getQueueSize() == null ? "unbounded" : info.getQueueSize());
     }
 
-    private static SizeValue queueSizeValue(int queueSize) {
-        return queueSize < 0 ? null : new SizeValue(queueSize);
-    }
-
     static class FixedExecutorSettings extends ExecutorBuilder.ExecutorSettings {
 
         private final int size;