fixed the case when you're not seeking, it didn't initalize

git-svn-id: file:///humgen/gsa-scr1/gsa-engineering/svn_contents/trunk@456 348d0f76-0448-11de-a6fe-93d51630548a

java/src/org/broadinstitute/sting/gatk/iterators/MergingSamRecordIterator2.java

@@ -111,6 +111,9 @@ public class MergingSamRecordIterator2 implements CloseableIterator<SAMRecord>,
 
     /** Returns true if any of the underlying iterators has more records, otherwise false. */
     public synchronized boolean hasNext() {
+        if (!initialized) {
+            lazyInitialization();
+        }
         return !this.pq.isEmpty();
     }