RFR: 8298087: XML Schema Validation reports an required attribute twice via ErrorHandler [v2]

[Joe Wang]

> Fix a copy n paste error in XMLSchemaValidator. When the patch was applied while updating to Xerces 2.12.2, the original code was not removed, resulting in reporting validation error twice.

Joe Wang has updated the pull request incrementally with one additional commit since the last revision:

  removing the line that changed locale. It's not necessary as the concern was the number of errors reported

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Changes:
  - all: https://git.openjdk.org/jdk/pull/13722/files
  - new: https://git.openjdk.org/jdk/pull/13722/files/7c4ba795..71609b1f

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=13722&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=13722&range=00-01

  Stats: 3 lines in 1 file changed: 0 ins; 3 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/13722.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13722/head:pull/13722

PR: https://git.openjdk.org/jdk/pull/13722