[HIPIFY][fix] Fix typo and functions' string arguments

+ Fix typo with missing comma in counterNames array
+ Change std::string argument to const std::string& argument in all functions

hipify-clang/src/StringUtils.h

@@ -11,4 +11,4 @@ llvm::StringRef unquoteStr(llvm::StringRef s);
 /**
   * If `s` starts with `prefix`, remove it. Otherwise, does nothing.
   */
-void removePrefixIfPresent(std::string &s, std::string prefix);
+void removePrefixIfPresent(std::string &s, const std::string& prefix);