Address some constParameter complaints from cppcheck

Author: martinhsv

src/utils/string.cc

@@ -225,7 +225,7 @@ void chomp(std::string *str) {
 }
 
 
-unsigned char x2c(unsigned char *what) {
+unsigned char x2c(const unsigned char *what) {
     unsigned char digit;
 
     digit = (what[0] >= 'A' ? ((what[0] & 0xdf) - 'A') + 10 : (what[0] - '0'));
@@ -239,7 +239,7 @@ unsigned char x2c(unsigned char *what) {
 /**
  * Converts a single hexadecimal digit into a decimal value.
  */
-unsigned char xsingle2c(unsigned char *what) {
+unsigned char xsingle2c(const unsigned char *what) {
     unsigned char digit;
 
     digit = (what[0] >= 'A' ? ((what[0] & 0xdf) - 'A') + 10 : (what[0] - '0'));

src/utils/string.h

@@ -73,8 +73,8 @@ void replaceAll(std::string *str, const std::string& from,
 std::string removeWhiteSpacesIfNeeded(std::string a);
 std::string parserSanitizer(std::string a);
 
-unsigned char x2c(unsigned char *what);
-unsigned char xsingle2c(unsigned char *what);
+unsigned char x2c(const unsigned char *what);
+unsigned char xsingle2c(const unsigned char *what);
 unsigned char *c2x(unsigned what, unsigned char *where);
 
 }  // namespace string

src/variables/variable.h

@@ -608,7 +608,7 @@ class Variables : public std::vector<Variable *> {
  public:
     bool contains(Variable *v) {
         return std::find_if(begin(), end(),
-            [v](Variable *m) -> bool { return *v == *m; }) != end();
+            [v](const Variable *m) -> bool { return *v == *m; }) != end();
     };
     bool contains(const VariableValue *v) {
         return std::find_if(begin(), end(),

test/cppcheck_suppressions.txt

@@ -80,8 +80,6 @@ missingInclude
 
 purgedConfiguration
 
-constParameter
-
 nullPointerRedundantCheck
 knownConditionTrueFalse
 cstyleCast