revert FileScan.equals change from this PR

Author: peter-toth

sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/v2/FileScan.scala

@@ -86,7 +86,7 @@ trait FileScan extends Scan
 
   override def equals(obj: Any): Boolean = obj match {
     case f: FileScan =>
-      fileIndex == f.fileIndex && readSchema == f.readSchema &&
+      fileIndex == f.fileIndex && readSchema == f.readSchema
         ExpressionSet(partitionFilters) == ExpressionSet(f.partitionFilters) &&
         ExpressionSet(dataFilters) == ExpressionSet(f.dataFilters)