Codefix: Earlier return from window functions which use window number.

[Rito13]

Motivation / Problem

The code for invalidating window data by class is faster than the one for invalidating by window number.

void InvalidateWindowClassesData(WindowClass cls, int data, bool gui_scope)
{
	for (Window *w : Window::Iterate()) {
		if (w->window_class == cls) {
			w->InvalidateData(data, gui_scope);
		}
	}
}

void InvalidateWindowData(WindowClass cls, WindowNumber number, int data, bool gui_scope)
{
	for (Window *w : Window::Iterate()) {
		if (w->window_class == cls && w->window_number == number) {
			w->InvalidateData(data, gui_scope);
		}
	}
}

Description

As window numbers are unique within a window class, it is not necessary to look for another window with the same class and number, so simply return.

Limitations

Checklist for review

Some things are not automated, and forgotten often. This list is a reminder for the reviewers.

• The bug fix is important enough to be backported? (label: 'backport requested')
• This PR touches english.txt or translations? Check the guidelines
• This PR affects the GS/AI API? (label 'needs review: Script API')
  • ai_changelog.hpp, game_changelog.hpp need updating.
  • The compatibility wrappers (compat_*.nut) need updating.
• This PR affects the NewGRF API? (label 'needs review: NewGRF')
  • newgrf_debug_data.h may need updating.
  • PR must be added to API tracker

[PeterN]

"Speed up" is quite the claim. But using an early return is none-the-less not a bad idea.