RFR: 8330524: Linux ppc64le compile warning with clang in os_linux_ppc.cpp

[Matthias Baesken]

When building with clang on Linux ppc64le, we run into this warning as error :

/open_jdk/jdk_test/jdk/src/hotspot/os_cpu/linux_ppc/os_linux_ppc.cpp:257:17: error: converting the result of '?:' with integer constants to a boolean always evaluates to 'true' [-Werror,-Wtautological-constant-compare]
      else if ((sig == USE_POLL_BIT_ONLY ? SIGTRAP : SIGSEGV) &&
                ^
1 error generated.

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Commit messages:
 - JDK-8330524

Changes: https://git.openjdk.org/jdk/pull/18818/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=18818&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8330524
  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/18818.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/18818/head:pull/18818

PR: https://git.openjdk.org/jdk/pull/18818