[FLINK-11004][Documentation] wrong ProcessWindowFunction.process argument in window document

[yuanyangwu]

What is the purpose of the change

Fix wrong argument of process() in JAVA and Scala example of Incremental Window Aggregation with ReduceFunction

Brief change log

• Fix wrong argument of process() in JAVA and Scala example of "Incremental Window Aggregation with ReduceFunction"

Verifying this change

This change is a trivial rework / code cleanup without any test coverage.

Does this pull request potentially affect one of the following parts:

• Dependencies (does it add or upgrade a dependency): no
• The public API, i.e., is any changed class annotated with @Public(Evolving): no
• The serializers: no
• The runtime per-record code paths (performance sensitive): no
• Anything that affects deployment or recovery: JobManager (and its components), Checkpointing, Yarn/Mesos, ZooKeeper: no
• The S3 file system connector: no

Documentation

• Does this pull request introduce a new feature? no
• If yes, how is the feature documented? not applicable

[sunjincheng121]

Hi @yuanyangwu Thanks for the PR!
After add space for ProcessWindowFunction[_,_,_,TimeWindow], the change looks good to me !
+1 to merged.
Thanks,
Jincheng

[shaoxuan-wang]

Hi @yuanyangwu , thanks for the contribution. It is always good to rebase the master whenever you add a new commit. I will help to merge this PR.