[clang-tidy] Reserve memory for vector loop

Found with performance-inefficient-vector-operation

Signed-off-by: Rosen Penev <rosenp@gmail.com>

src/Hooks.cpp

@@ -196,6 +196,7 @@ void Hooks::onExit () const
 
     // Convert to a vector of strings.
     std::vector <std::string> input;
+    input.reserve(tasks.size());
     for (auto& t : tasks)
       input.push_back (t.composeJSON ());
 

src/feedback.cpp

@@ -47,6 +47,7 @@ static void countTasks (const std::vector <Task>&, const std::string&, int&, int
 std::string taskIdentifiers (const std::vector <Task>& tasks)
 {
   std::vector <std::string> identifiers;
+  identifiers.reserve(tasks.size());
   for (const auto& task: tasks)
     identifiers.push_back (task.identifier (true));