Cppcheck: decrease variable scope

common.cpp

@@ -105,8 +105,6 @@ void show_histogram(const std::map<std::string, int>& data, const std::string& c
 }
 
 void show_nested_histogram(const Caches& cc, std::string Cache::*ptr, std::string Cache::*ptr2, const std::string& caption, bool html, bool sort_by_val) {
-	int HIST_MAX = 20;
-
 	std::map<std::string, int> histogram;
 	std::vector<std::pair<std::string, int>> pairs;
 
@@ -120,7 +118,9 @@ void show_nested_histogram(const Caches& cc, std::string Cache::*ptr, std::strin
 		sort(pairs.begin(), pairs.end(), [&](std::pair<std::string, int>& a, std::pair<std::string, int>& b) { return a.first < b.first; });
 
 	if (html) {
+		int HIST_MAX = 20;
 		int max;
+
 		if (sort_by_val)
 			max = pairs[0].second;
 		else