SONAR suggestion - problems with string format calls

Change-Id: Ie6b985d2e4db79d6398b17e38a680920f52366b3
diff --git a/cli/src/main/java/org/onosproject/cli/net/DpisListCommand.java b/cli/src/main/java/org/onosproject/cli/net/DpisListCommand.java
index 6bdcedb..d34c9ed 100644
--- a/cli/src/main/java/org/onosproject/cli/net/DpisListCommand.java
+++ b/cli/src/main/java/org/onosproject/cli/net/DpisListCommand.java
@@ -213,7 +213,7 @@
     }
 
     private void printDpiStatisticsJson(int number, DpiStatistics ds) {
-        String index = number < 0 ? String.format("  -  ") : String.format("%5d", number);
+        String index = number < 0 ? "  -  " : String.format("%5d", number);
         if ("".equals(ds.receivedTime())) {
             print("ReceivedTime is null, No valid DPI Statistics!");
             return;
@@ -226,7 +226,7 @@
 
     private void printDpiStatisticsClass(int number, DpiStatistics ds) {
         String printLine = "";
-        String index = number < 0 ? String.format("  -  ") : String.format("%5d", number);
+        String index = number < 0 ? "  -  " : String.format("%5d", number);
 
         DpiStatInfo dsi = ds.dpiStatInfo();
         if (dsi == null) {