SONAR suggestions - prevent truncation of arithmetic expressions

Change-Id: I4694c0c3183b991a4f0db793f584bc77a5fb7d60
diff --git a/apps/cpman/app/src/main/java/org/onosproject/cpman/gui/CpmanViewMessageHandler.java b/apps/cpman/app/src/main/java/org/onosproject/cpman/gui/CpmanViewMessageHandler.java
index 8f64844..873d23d 100644
--- a/apps/cpman/app/src/main/java/org/onosproject/cpman/gui/CpmanViewMessageHandler.java
+++ b/apps/cpman/app/src/main/java/org/onosproject/cpman/gui/CpmanViewMessageHandler.java
@@ -179,7 +179,7 @@
                     local.put(StringUtils.lowerCase(cmt.name()), data.get(cmt)[i]);
                 }
 
-                String calculated = time.minusMinutes(numOfDp - i).format(TIME_FORMAT);
+                String calculated = time.minusMinutes((long) numOfDp - i).format(TIME_FORMAT);
 
                 local.put(LABEL, calculated);
                 populateMetric(cm.addDataPoint(calculated), local);