Bug fix; need a barrier at the end of the BW tests so that the master

knows that some tests failed. Otherwise we say all test completed
okay, and then print a bunch of errors!

event/linktest/linktest.pl.in

@@ -816,7 +816,8 @@ sub bw_test {
 	    }
 	}
     }
-    
+    # wait for completion before termination so that all errors reported in.
+    &barrier();
 }