RFR: 8368606: Printer lookup returns empty on AIX platform due to uninitialized results list

[Ravi-Patel8]

Bug Ref: https://bugs.openjdk.org/browse/JDK-8368606

As part of [JDK-8344057](https://bugs.openjdk.org/browse/JDK-8344057) ("Remove doPrivileged calls from unix platform sources in the java.desktop module"), changes were made to execCmd() in
 `src/java.desktop/unix/classes/sun/print/PrintServiceLookupProvider.java`.
In the updated implementation, execCmd(...) code is missing to initialize the results variable. It declares it as null and then tries to results.add(line), which prevents the results list from being populated with printer names.

Initializing the results variable will resolve the issue.


Signed-off-by: Ravi.Patel8 <Ravi.Patel8 at ibm.com>

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Commit messages:
 - 8368606: Init results in PrintServiceLookupProvider.execCmd

Changes: https://git.openjdk.org/jdk/pull/27482/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=27482&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8368606
  Stats: 1 line in 1 file changed: 1 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/27482.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27482/head:pull/27482

PR: https://git.openjdk.org/jdk/pull/27482