6858: Thread dump does not show complete call stack based for all thr…

…eads (grouped by time)

Reviewed-by: ghb

application/org.openjdk.jmc.flightrecorder.ui/src/main/java/org/openjdk/jmc/flightrecorder/ui/pages/ThreadDumpsPage.java

@@ -439,7 +439,7 @@ private static ThreadDumpCollection parseCollection(String title, String str) {
 		if (parts.length > 2) {
 			ThreadDump[] dumps = new ThreadDump[parts.length - 2];
 			ThreadDumpCollection parent = new ThreadDumpCollection(title,
-					parts[0] + SEPARATOR + parts[parts.length - 1], dumps);
+					str, dumps);
 			for (int i = 0; i < dumps.length; i++) {
 				dumps[i] = parseThreadDump(parts[i + 1], parent);
 			}