RFR: 8313631: SA: stack trace printed using "where" command does not show class name

[Ashutosh Mehra]

Please review trivial fix to display class name in the output of "where" command of SA.

Testing: hotspot_serviceability

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Commit messages:
 - 8313631: SA: stack trace printed using "where" command does not show class name

Changes: https://git.openjdk.org/jdk/pull/15952/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=15952&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8313631
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/15952.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15952/head:pull/15952

PR: https://git.openjdk.org/jdk/pull/15952