RFR: 8343471: RISC-V: compiler/cpuflags/TestAESIntrinsicsOnUnsupportedConfig.java fails after JDK-8334999

[Fei Yang]

Hi, please review this small change.

The test expects a message like `warning: AES instructions are not available on this CPU` for all cpu platforms without AES support. After https://bugs.openjdk.org/browse/JDK-8334999, we report this `warning: AES intrinsics require Zvkn extension (not available on this CPU)` on RISC-V platforms where `Zvkn` extension is not available. Patch fixes this message making it consistent with other CPU platforms. Same test passes with this fix.

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Commit messages:
 - 8343471: RISC-V: compiler/cpuflags/TestAESIntrinsicsOnUnsupportedConfig.java fails after JDK-8334999

Changes: https://git.openjdk.org/jdk/pull/21847/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=21847&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8343471
  Stats: 19 lines in 1 file changed: 9 ins; 5 del; 5 mod
  Patch: https://git.openjdk.org/jdk/pull/21847.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21847/head:pull/21847

PR: https://git.openjdk.org/jdk/pull/21847