[SPARK-15132][MINOR][SQL] Debug log for generated code should be printed with proper indentation

## What changes were proposed in this pull request?

Similar to #11990, GenerateOrdering and GenerateColumnAccessor should print debug log for generated code with proper indentation.

## How was this patch tested?

Manually checked.

Author: Kousuke Saruta <sarutak@oss.nttdata.co.jp>

Closes #12908 from sarutak/SPARK-15132.

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/codegen/GenerateOrdering.scala

@@ -136,7 +136,7 @@ object GenerateOrdering extends CodeGenerator[Seq[SortOrder], Ordering[InternalR
         }
       }"""
 
-    logDebug(s"Generated Ordering: ${CodeFormatter.format(code)}")
+    logDebug(s"Generated Ordering by ${ordering.mkString(",")}:\n${CodeFormatter.format(code)}")
 
     CodeGenerator.compile(code).generate(ctx.references.toArray).asInstanceOf[BaseOrdering]
   }

sql/core/src/main/scala/org/apache/spark/sql/execution/columnar/GenerateColumnAccessor.scala

@@ -224,7 +224,7 @@ object GenerateColumnAccessor extends CodeGenerator[Seq[DataType], ColumnarItera
         }
       }"""
 
-    logDebug(s"Generated ColumnarIterator: ${CodeFormatter.format(code)}")
+    logDebug(s"Generated ColumnarIterator:\n${CodeFormatter.format(code)}")
 
     CodeGenerator.compile(code).generate(Array.empty).asInstanceOf[ColumnarIterator]
   }