[MINOR] fix a typo in BroadcastJoinSuite

## What changes were proposed in this pull request?

`BroadcastNestedLoopJoinExec` should be `BroadcastHashJoinExec`

## How was this patch tested?

N/A

Author: Wenchen Fan <wenchen@databricks.com>

Closes #20202 from cloud-fan/typo.

sql/core/src/test/scala/org/apache/spark/sql/execution/joins/BroadcastJoinSuite.scala

@@ -318,7 +318,7 @@ class BroadcastJoinSuite extends QueryTest with SQLTestUtils {
       case b: BroadcastNestedLoopJoinExec =>
         assert(b.getClass.getSimpleName === joinMethod)
         assert(b.buildSide === buildSide)
-      case b: BroadcastNestedLoopJoinExec =>
+      case b: BroadcastHashJoinExec =>
         assert(b.getClass.getSimpleName === joinMethod)
         assert(b.buildSide === buildSide)
       case w: WholeStageCodegenExec =>