Updated example and docs for GetArrowBatches

Updated the example and documentation for GetArrowBatches to include releasing the arrow batch.
Signed-off-by: Raymond Cypher <raymond.cypher@databricks.com>

Author: rcypher-databricks

doc.go

@@ -322,6 +322,7 @@ Example usage:
 			log.Printf("batch %v: nRecords=%v\n", iBatch, b.NumRows())
 			iBatch += 1
 			nRows += int(b.NumRows())
+			b.Release()
 		}
 		log.Printf("NRows: %v\n", nRows)
 	}

examples/arrrowbatches/main.go

@@ -89,6 +89,7 @@ func loopWithHasNext(db *sql.DB) {
 		log.Printf("batch %v: nRecords=%v\n", iBatch, b.NumRows())
 		iBatch += 1
 		nRows += int(b.NumRows())
+		b.Release()
 	}
 	log.Printf("NRows: %v\n", nRows)
 }
@@ -128,6 +129,7 @@ func loopWithNext(db *sql.DB) {
 		log.Printf("batch %v: nRecords=%v\n", iBatch, b.NumRows())
 		iBatch += 1
 		nRows += int(b.NumRows())
+		b.Release()
 	}
 
 	log.Printf("NRows: %v\n", nRows)