quick bug fix.

git-svn-id: file:///humgen/gsa-scr1/gsa-engineering/svn_contents/trunk@5296 348d0f76-0448-11de-a6fe-93d51630548a

java/src/org/broadinstitute/sting/gatk/walkers/PrintReadsWalker.java

@@ -116,7 +116,7 @@ public class PrintReadsWalker extends ReadWalker<SAMRecord, SAMFileWriter> {
      * @return the SAMFileWriter, so that the next reduce can emit to the same source
      */
     public SAMFileWriter reduce( SAMRecord read, SAMFileWriter output ) {
-        out.addAlignment(read);
+        output.addAlignment(read);
         return output;
     }