[SPARK-18118][SQL] fix a compilation error due to nested JavaBeans

Remove this reference.

(cherry picked from commit 70dfdcbb)
Signed-off-by: Herman van Hovell <hvanhovell@databricks.com>

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/objects/objects.scala

@@ -905,7 +905,7 @@ case class InitializeJavaBean(beanInstance: Expression, setters: Map[String, Exp
         val fieldGen = fieldValue.genCode(ctx)
         s"""
            ${fieldGen.code}
-           this.${javaBeanInstance}.$setterMethod(${fieldGen.value});
+           ${javaBeanInstance}.$setterMethod(${fieldGen.value});
          """
     }
     val initializeCode = ctx.splitExpressions(ctx.INPUT_ROW, initialize.toSeq)