Reduce execution time

tests/main/execute_on_a_specific_worker.c

@@ -28,6 +28,8 @@
  */
 
 #ifdef STARPU_QUICK_CHECK
+  #define N 10
+#elif !defined(STARPU_LONG_CHECK)
   #define N 100
 #else
   #define N 1000

tests/microbenchs/prefetch_data_on_node.c

@@ -27,9 +27,11 @@
  */
 
 #ifdef STARPU_QUICK_CHECK
-#define N		100
+  #define N 10
+#elif !defined(STARPU_LONG_CHECK)
+  #define N 100
 #else
-#define N		1000
+  #define N 1000
 #endif
 
 #define VECTORSIZE	1024