7009998: JMX synchronization during connection restart is faulty

Add a return statement after the re-connecting has finished and the state is CONNECTED

Reviewed-by: sjiang

jdk/make/netbeans/jmx/build.properties

@@ -38,6 +38,7 @@ excludes=\
     com/sun/jmx/snmp/
 
 jtreg.tests=\
+    com/sun/jmx/ \
     com/sun/management/ \
     java/lang/management/ \
     javax/management/

jdk/src/share/classes/com/sun/jmx/remote/internal/ClientCommunicatorAdmin.java

@@ -115,6 +115,7 @@ public abstract class ClientCommunicatorAdmin {
                     // restarted is failed by another thread
                     throw ioe;
                 }
+                return;
             } else {
                 state = RE_CONNECTING;
                 lock.notifyAll();