Review request: 8042205: javax/management/monitor/*: some test didn't get all the notifications

[shanliang]

Hi,

Please review the following fix, I changed the way to check received 
notifications.

Bug: https://bugs.openjdk.java.net/browse/JDK-8042205
Webrec: http://cr.openjdk.java.net/~sjiang/JDK-8042205/00/ 
<http://cr.openjdk.java.net/%7Esjiang/JDK-8042205/00/>

Thanks, shanliang