ARROW-11343: [Rust][DataFusion] Simplified example with UDF.
ARROW-11343: [Rust][DataFusion] Simplified example with UDF.

I.e. use `collect` instead of the builder, which is simpler and faster

Closes #9290 from jorgecarleitao/simpler_udf

Authored-by: Jorge C. Leitao <dfffc62510208f06492f17a48dc6ce87aa15abf6@gmail.com>
Signed-off-by: Andrew Lamb <02e0a999c50b1f88df7a8f5a04e1b76b35ea6a88@nerdnetworks.org>

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