RFR: 8337840: Remove redundant null check in ObjectOutputStream.writeProxyDesc

[Andrey Turbanov]

There is implicit null check in line before.

https://github.com/openjdk/jdk/blob/431d4f7e18369466eedd00926a5162a1461d0b25/src/java.base/share/classes/java/io/ObjectOutputStream.java#L1267-L1277

'cl' can't be null after that.

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

Commit messages:
 - [PATCH] Remove redundant null check in ObjectOutputStream.writeProxyDesc

Changes: https://git.openjdk.org/jdk/pull/20351/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=20351&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8337840
  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/20351.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20351/head:pull/20351

PR: https://git.openjdk.org/jdk/pull/20351