Solve issues in benchmarks.

Author: viferga

source/benchmarks/set_bench/source/set_bench.cpp

@@ -35,6 +35,9 @@ class set_bench : public benchmark::Fixture
 	{
 		s = set_create(&hash_callback_ptr, &comparable_callback_ptr);
 
+		keys.clear();
+		values.clear();
+
 		keys.reserve(SET_SIZE);
 		values.reserve(SET_SIZE);
 

source/benchmarks/set_small_bench/source/set_small_bench.cpp

@@ -35,6 +35,9 @@ class set_small_bench : public benchmark::Fixture
 	{
 		s = set_small_create(SET_SIZE);
 
+		keys.clear();
+		values.clear();
+
 		keys.reserve(SET_SIZE);
 		values.reserve(SET_SIZE);