[Rev 01] RFR: 6825: JMX defineEventProbes fails when no events in XMLDescriptor

[Jessye Coleman-Shapiro]

> This patch makes the agent JMX operation 'defineEventProbes' accept an xmlDecsription with no event tags.  Previously,
> the only way you could clear all current transforms was to supply the operation with an empty or null xmlDescription.
> Now a file with the following structure will also clear all current transforms:
> `<jfragent><events></events></jfragent>`

Jessye Coleman-Shapiro has updated the pull request incrementally with one additional commit since the last revision:

  Fix style issue

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Changes:
  - all: https://git.openjdk.java.net/jmc/pull/80/files
  - new: https://git.openjdk.java.net/jmc/pull/80/files/657db252..fc53d1c7

Webrevs:
 - full: https://webrevs.openjdk.java.net/jmc/80/webrev.01
 - incr: https://webrevs.openjdk.java.net/jmc/80/webrev.00-01

  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.java.net/jmc/pull/80.diff
  Fetch: git fetch https://git.openjdk.java.net/jmc pull/80/head:pull/80

PR: https://git.openjdk.java.net/jmc/pull/80