RFR: 8368606: Printer lookup returns empty on AIX platform due to uninitialized results list [v2]

[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>

Ravi-Patel8 has updated the pull request incrementally with two additional commits since the last revision:

 - Updated Comments
   
   Signed-off-by: Ravi.Patel8 <Ravi.Patel8 at ibm.com>
 - Add catch block to log exception details for troubleshooting printer
   command
   
   Signed-off-by: Ravi.Patel8 <Ravi.Patel8 at ibm.com>

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/27482/files
  - new: https://git.openjdk.org/jdk/pull/27482/files/92c3ec8e..80fcec26

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=27482&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=27482&range=00-01

  Stats: 4 lines in 1 file changed: 3 ins; 0 del; 1 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