[SPARK-33456][SQL][TEST][FOLLOWUP] Fix SUBEXPRESSION_ELIMINATION_ENAB…

…LED config name

### What changes were proposed in this pull request?

To fix wrong config name in `subexp-elimination.sql`.

### Why are the changes needed?

`CONFIG_DIM` should use config name's key.

### Does this PR introduce _any_ user-facing change?

No, dev only.

### How was this patch tested?

Unit test.

Closes #30384 from viirya/SPARK-33456-followup.

Authored-by: Liang-Chi Hsieh <viirya@gmail.com>
Signed-off-by: HyukjinKwon <gurwls223@apache.org>

sql/core/src/test/resources/sql-tests/inputs/subexp-elimination.sql

@@ -8,8 +8,8 @@
 --CONFIG_DIM2 spark.sql.codegen.factoryMode=CODEGEN_ONLY
 --CONFIG_DIM2 spark.sql.codegen.factoryMode=NO_CODEGEN
 
---CONFIG_DIM3 SUBEXPRESSION_ELIMINATION_ENABLED=true
---CONFIG_DIM3 SUBEXPRESSION_ELIMINATION_ENABLED=false
+--CONFIG_DIM3 spark.sql.subexpressionElimination.enabled=true
+--CONFIG_DIM3 spark.sql.subexpressionElimination.enabled=false
 
 -- Test data.
 CREATE OR REPLACE TEMPORARY VIEW testData AS SELECT * FROM VALUES