tests/microbenchs/async_tasks_overhead.c: free memory

tests/microbenchs/async_tasks_overhead.c

@@ -1,7 +1,7 @@
 /* StarPU --- Runtime system for heterogeneous multicore architectures.
  *
  * Copyright (C) 2010-2014  Université de Bordeaux
- * Copyright (C) 2010, 2011, 2012, 2013  Centre National de la Recherche Scientifique
+ * Copyright (C) 2010, 2011, 2012, 2013, 2015  Centre National de la Recherche Scientifique
  *
  * StarPU is free software; you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as published by
@@ -179,5 +179,6 @@ enodev:
 	/* yes, we do not perform the computation but we did detect that no one
  	 * could perform the kernel, so this is not an error from StarPU */
 	starpu_shutdown();
+	free(tasks);
 	return STARPU_TEST_SKIPPED;
 }