Revert "fix"

This reverts commit 9bad173.

Author: viirya

spark/src/main/scala/org/apache/comet/CometSparkSessionExtensions.scala

@@ -1084,7 +1084,7 @@ class CometSparkSessionExtensions
     override def apply(plan: SparkPlan): SparkPlan = {
       val eliminatedPlan = plan transformUp {
         case ColumnarToRowExec(sparkToColumnar: CometSparkToColumnarExec) => sparkToColumnar.child
-        case c @ ColumnarToRowExec(child) if child.exists(_.isInstanceOf[CometPlan]) =>
+        case c @ ColumnarToRowExec(child) =>
           val op = CometColumnarToRowExec(child)
           if (c.logicalLink.isEmpty) {
             op.unsetTagValue(SparkPlan.LOGICAL_PLAN_TAG)