Merge pull request #4237 from StefanSpieker/negating_result_compareto

Spotbugs: changed order for compare instead of negating result 

core/src/main/java/hudson/Functions.java

@@ -1059,8 +1059,8 @@ public class Functions {
         }
 
         public int compareTo(Tag that) {
-            int r = Double.compare(this.ordinal, that.ordinal);
-            if (r!=0)   return -r; // descending for ordinal
+            int r = Double.compare(that.ordinal, this.ordinal);
+            if (r!=0)   return r; // descending for ordinal by reversing the order for compare
             return this.hierarchy.compareTo(that.hierarchy);
         }
     }

core/src/main/java/hudson/model/RunMap.java

@@ -156,7 +156,7 @@ public final class RunMap<R extends Run<?,R>> extends AbstractLazyLoadRunMap<R>
     @Deprecated
     public static final Comparator<Comparable> COMPARATOR = new Comparator<Comparable>() {
         public int compare(Comparable o1, Comparable o2) {
-            return -o1.compareTo(o2);
+            return o2.compareTo(o1);
         }
     };