fix java.lang.ClassCastException

get Exception when run：bin/run-example org.apache.spark.examples.sql.RDDRelation
Exception's detail is:
Exception in thread "main" java.lang.ClassCastException: java.lang.Long cannot be cast to java.lang.Integer
	at scala.runtime.BoxesRunTime.unboxToInt(BoxesRunTime.java:106)
	at org.apache.spark.sql.catalyst.expressions.GenericRow.getInt(Row.scala:145)
	at org.apache.spark.examples.sql.RDDRelation$.main(RDDRelation.scala:49)
	at org.apache.spark.examples.sql.RDDRelation.main(RDDRelation.scala)
change sql("SELECT COUNT(*) FROM records").collect().head.getInt(0) to sql("SELECT COUNT(*) FROM records").collect().head.getLong(0), then the Exception do not occur any more

Author: baishuo(白硕) <vc_java@hotmail.com>

Closes #949 from baishuo/master and squashes the following commits:

f4b319f [baishuo(白硕)] fix java.lang.ClassCastException

examples/src/main/scala/org/apache/spark/examples/sql/RDDRelation.scala

@@ -43,7 +43,7 @@ object RDDRelation {
     sql("SELECT * FROM records").collect().foreach(println)
 
     // Aggregation queries are also supported.
-    val count = sql("SELECT COUNT(*) FROM records").collect().head.getInt(0)
+    val count = sql("SELECT COUNT(*) FROM records").collect().head.getLong(0)
     println(s"COUNT(*): $count")
 
     // The results of SQL queries are themselves RDDs and support all normal RDD functions.  The