[lworld] RFR: 8267698: [lworld] [lw3] runtime\exceptionMsgs\NullPointerException\NullPointerExceptionTest.java test fails because of new error message

[Frederic Parain]

Fix test to recognize the new exception message.

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Commit messages:
 - Fix NPE message test

Changes: https://git.openjdk.java.net/valhalla/pull/426/files
 Webrev: https://webrevs.openjdk.java.net/?repo=valhalla&pr=426&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8267698
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/valhalla/pull/426.diff
  Fetch: git fetch https://git.openjdk.java.net/valhalla pull/426/head:pull/426

PR: https://git.openjdk.java.net/valhalla/pull/426