SONAR suggestions - prevent truncation of arithmetic expressions

Change-Id: I4694c0c3183b991a4f0db793f584bc77a5fb7d60
diff --git a/drivers/default/src/main/java/org/onosproject/driver/pipeline/SpringOpenTTP.java b/drivers/default/src/main/java/org/onosproject/driver/pipeline/SpringOpenTTP.java
index 2a5a024..4376295 100644
--- a/drivers/default/src/main/java/org/onosproject/driver/pipeline/SpringOpenTTP.java
+++ b/drivers/default/src/main/java/org/onosproject/driver/pipeline/SpringOpenTTP.java
@@ -144,7 +144,7 @@
         // ONOS-3579 workaround, let core threads die out on idle
         if (GROUP_CHECKER instanceof ScheduledThreadPoolExecutor) {
             ScheduledThreadPoolExecutor executor = (ScheduledThreadPoolExecutor) GROUP_CHECKER;
-            executor.setKeepAliveTime(CHECK_DELAY * 2, TimeUnit.MILLISECONDS);
+            executor.setKeepAliveTime(CHECK_DELAY * 2L, TimeUnit.MILLISECONDS);
             executor.allowCoreThreadTimeOut(true);
         }
     }