Add missing #include <stdio.h>.

Author: petervdonovan

C/Savina/src/BenchmarkRunner.lf

@@ -34,6 +34,11 @@ target C;
  * @author Matt Chorlian
  * @author Arthur Deng
  */
+
+preamble {=
+    #include <stdio.h>
+=}
+
 reactor BenchmarkRunner(num_iterations:int(12)) {
 
     /** Signal to start execution. Set this input from a startup reaction in the main reactor. */

C/Savina/src/parallelism/Trapezoidal.lf

@@ -31,6 +31,7 @@ target C {
 
 import BenchmarkRunner from "../BenchmarkRunner.lf";
 preamble {=
+    #include <stdio.h>
     #include "benchmark_runner.h"
     typedef struct WorkMessage {