RFR: 8365307: AIX make fails after JDK-8364611

[Matthias Baesken]

After recent change [JDK-8364611](https://bugs.openjdk.org/browse/JDK-8364611), the build fails on AIX with :


/priv/jenkins/client-home/workspace/openjdk-jdk-aix_ppc64-opt/jdk/test/jdk/java/lang/ProcessBuilder/childSignalDisposition/exePrintSignalDisposition.c:75:41: error: format specifies type 'unsigned int' but the argument has type 'sigset_t' (aka 'struct sigset_t') [-Werror,-Wformat]
   75 | printf("%X %X\n", act.sa_flags, act.sa_mask);
      | ~~ ^~~~~~~~~~~


The printing of the mask is optional and not needed for a working test, so we can avoid it on AIX .

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Commit messages:
 - JDK-8365307

Changes: https://git.openjdk.org/jdk/pull/26739/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=26739&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8365307
  Stats: 4 lines in 1 file changed: 4 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/26739.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/26739/head:pull/26739

PR: https://git.openjdk.org/jdk/pull/26739