[SPARK-14268][SQL] rename toRowExpressions and fromRowExpression to serializer and deserializer in ExpressionEncoder

## What changes were proposed in this pull request?

In `ExpressionEncoder`, we use `constructorFor` to build `fromRowExpression` as the `deserializer` in `ObjectOperator`. It's kind of confusing, we should make the name consistent.

## How was this patch tested?

existing tests.

Author: Wenchen Fan <wenchen@databricks.com>

Closes #12058 from cloud-fan/rename.

1 files changed, 2 insertions, 2 deletions

diff --git a/sql/core/src/test/scala/org/apache/spark/sql/QueryTest.scala b/sql/core/src/test/scala/org/apache/spark/sql/QueryTest.scala
index 7ff4ffcaec..854a662cc4 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/QueryTest.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/QueryTest.scala
@@ -90,7 +90,7 @@ abstract class QueryTest extends PlanTest {
           s"""
              |Exception collecting dataset as objects
              |${ds.resolvedTEncoder}
-             |${ds.resolvedTEncoder.fromRowExpression.treeString}
+             |${ds.resolvedTEncoder.deserializer.treeString}
              |${ds.queryExecution}
            """.stripMargin, e)
     }
@@ -109,7 +109,7 @@ abstract class QueryTest extends PlanTest {
       fail(
         s"""Decoded objects do not match expected objects:
             |$comparision
-            |${ds.resolvedTEncoder.fromRowExpression.treeString}
+            |${ds.resolvedTEncoder.deserializer.treeString}
          """.stripMargin)
     }
   }