RFR: JDK-8262428: doclint warnings in java.xml module

[Jonathan Gibbons]

Please review a small doc fix to remove some superfluous `<p>` tags and an erroneous `</tr>` tag, all reported by doclint..

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Commit messages:
 - JDK-8262428: doclint warnings in java.xml module

Changes: https://git.openjdk.java.net/jdk/pull/2733/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=2733&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8262428
  Stats: 7 lines in 1 file changed: 0 ins; 5 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk/pull/2733.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/2733/head:pull/2733

PR: https://git.openjdk.java.net/jdk/pull/2733