ARROW-11959: [Rust][DataFusion] Fix log line
ARROW-11959: [Rust][DataFusion] Fix log line

Just a small fix to fix a debug line. It was printing the unoptimized plan instead of the optimized plan.

Closes #9699 from Dandandan/fix_logging

Authored-by: Heres, Daniel <61924dac3230581b78b62e9e0cd0f8203281db27@gmail.com>
Signed-off-by: Andrew Lamb <02e0a999c50b1f88df7a8f5a04e1b76b35ea6a88@nerdnetworks.org>

icexelloss/arrow,wesm/arrow,apache/arrow,cpcloud/arrow,kou/arrow,laurentgo/arrow,apache/arrow,laurentgo/arrow,apache/arrow,kou/arrow,cpcloud/arrow,icexelloss/arrow,laurentgo/arrow,icexelloss/arrow,kou/arrow,kou/arrow,apache/arrow,cpcloud/arrow,kou/arrow,kou/arrow,cpcloud/arrow,apache/arrow,laurentgo/arrow,icexelloss/arrow,laurentgo/arrow,laurentgo/arrow,icexelloss/arrow,kou/arrow,apache/arrow,cpcloud/arrow,kou/arrow,kou/arrow,laurentgo/arrow,laurentgo/arrow,laurentgo/arrow,apache/arrow,laurentgo/arrow,wesm/arrow,laurentgo/arrow,cpcloud/arrow,laurentgo/arrow,icexelloss/arrow,icexelloss/arrow,kou/arrow,wesm/arrow,apache/arrow,cpcloud/arrow,icexelloss/arrow,cpcloud/arrow,icexelloss/arrow,laurentgo/arrow,icexelloss/arrow,wesm/arrow,icexelloss/arrow,wesm/arrow,wesm/arrow,cpcloud/arrow,apache/arrow,apache/arrow,apache/arrow,cpcloud/arrow,wesm/arrow,cpcloud/arrow,laurentgo/arrow,apache/arrow,kou/arrow,cpcloud/arrow,wesm/arrow,kou/arrow,kou/arrow,wesm/arrow,apache/arrow,wesm/arrow,wesm/arrow,cpcloud/arrow,cpcloud/arrow,laurentgo/arrow,icexelloss/arrow,wesm/arrow,wesm/arrow,wesm/arrow,apache/arrow,kou/arrow,icexelloss/arrow,icexelloss/arrow