[SPARK-17101][SQL] Provide consistent format identifiers for TextFileFormat and ParquetFileFormat

Author: jaceklaskowski

sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/parquet/ParquetFileFormat.scala

@@ -60,7 +60,7 @@ class ParquetFileFormat
 
   override def shortName(): String = "parquet"
 
-  override def toString: String = "ParquetFormat"
+  override def toString: String = shortName.toUpperCase
 
   override def hashCode(): Int = getClass.hashCode()
 

sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/text/TextFileFormat.scala

@@ -40,6 +40,8 @@ class TextFileFormat extends TextBasedFileFormat with DataSourceRegister {
 
   override def shortName(): String = "text"
 
+  override def toString: String = shortName.toUpperCase
+
   private def verifySchema(schema: StructType): Unit = {
     if (schema.size != 1) {
       throw new AnalysisException(