RFR(XS): 8202415: Incorrect time logged for monitor deflation

[Daniel D. Daugherty]

Greetings,

I have an extra small fix for the following bug:

     JDK-8202415 Incorrect time logged for monitor deflation
     https://bugs.openjdk.java.net/browse/JDK-8202415

Here's the webrev URL:

http://cr.openjdk.java.net/~dcubed/8202415-webrev/0_for_jdk_jdk/

The fix has been tested with a Mach5 builds-tier1,hs-tier1,jdk-tier1,
hs-tier2,hs-tier3 job. The modified SafepointCleanupTest.java has
been verified to pass in all Mach5 configs.

This bug is currently targeted at jdk13, but I think it is safe
enough to be pushed to jdk12 if the reviewers agree.

Thanks, in advance, for any comments, questions or suggestions.

Dan