one more scope for benchmarks

tests/bench.h

@@ -25,6 +25,7 @@ typedef struct {
 
 
 #define BENCHMARK(name) \
+    { \
         bench B; B.N = 5000000; B.R = 3; \
         bench_start(&B); \
         for (int _r = 0; _r < B.R ; _r++ ) { \
@@ -33,7 +34,9 @@ typedef struct {
 #define END_BENCHMARK() \
             } \
         } \
-    bench_stop(&B);
+        bench_stop(&B); \
+    }
+
 
 
 long unixtime();