[SQL] Fix serializability of ORC table scan

A follow-up to #6244.

Author: Michael Armbrust <michael@databricks.com>

Closes #6247 from marmbrus/fixOrcTests and squashes the following commits:

e39ee1b [Michael Armbrust] [SQL] Fix serializability of ORC table scan

sql/hive/src/main/scala/org/apache/spark/sql/hive/orc/OrcRelation.scala

@@ -195,7 +195,7 @@ private[orc] case class OrcTableScan(
     attributes: Seq[Attribute],
     @transient relation: OrcRelation,
     filters: Array[Filter],
-    inputPaths: Array[FileStatus])
+    @transient inputPaths: Array[FileStatus])
   extends Logging
   with HiveInspectors {