ORC-1587: Fix usage command of SparkBenchmark document

### What changes were proposed in this pull request?
```
java -jar spark/target/orc-benchmarks-spark-${ORC_VERSION}.jar spark data
```

### Why are the changes needed?
```bash
java -jar spark/target/orc-benchmarks-spark-*.jar spark data
```

```
Error: Invalid or corrupt jarfile spark/target/orc-benchmarks-spark-2.1.0-SNAPSHOT-nohive.jar
```

### How was this patch tested?
local test

### Was this patch authored or co-authored using generative AI tooling?
No

Closes #1749 from cxzl25/ORC-1587.

Authored-by: sychen <[email protected]>
Signed-off-by: Dongjoon Hyun <[email protected]>

Author: cxzl25

java/bench/README.md

@@ -38,7 +38,8 @@ To run full read benchmark:
 
 ```% java -jar hive/target/orc-benchmarks-hive-*-uber.jar read-all data```
 
-To run a write benchmark: 
+To run a write benchmark:
+
 ```% java -jar hive/target/orc-benchmarks-hive-*-uber.jar write data```
 
 To run column projection benchmark:
@@ -55,5 +56,5 @@ To run row-filter benchmark:
 
 To run spark benchmark:
 
-```% java -jar spark/target/orc-benchmarks-spark-*.jar spark data```
+```% java -jar spark/target/orc-benchmarks-spark-${ORC_VERSION}.jar spark data```