[Examples] mouse-state example seems to have its outputs switched

[MichaelZalla]

In the mouse-state example, the changes to the mouse's button states are logged as "${new_buttons} -> ${old_buttons}":

rust-sdl2/examples/mouse-state.rs

Lines 40 to 51 in f2f1e29

	// Get the difference between the new and old sets.
	let new_buttons = &buttons - &prev_buttons;
	let old_buttons = &prev_buttons - &buttons;
	if !new_buttons.is_empty() || !old_buttons.is_empty() {
	println!(
	"X = {:?}, Y = {:?} : {:?} -> {:?}",
	state.x(),
	state.y(),
	new_buttons,
	old_buttons
	);

A left-click (mouse-down, then mouse-up) inside the window generates this output:

X = 605, Y = 300 : {Left} -> {}
X = 605, Y = 300 : {} -> {Left}

Shouldn't this order be reversed? I would expect to see:

X = 605, Y = 300 : {} -> {Left}
X = 605, Y = 300 : {Left} -> {}

More output:

X = 605, Y = 300 : {Left} -> {}
X = 605, Y = 300 : {} -> {Left}
X = 828, Y = 161 : {Right} -> {}
X = 828, Y = 161 : {} -> {Right}
X = 232, Y = 312 : {Left} -> {}
X = 232, Y = 312 : {} -> {Left}
X = 234, Y = 337 : {Left} -> {}
X = 234, Y = 337 : {} -> {Left}
X = 712, Y = 134 : {Right} -> {}
X = 712, Y = 134 : {} -> {Right}
X = 813, Y = 283 : {Right} -> {}
X = 813, Y = 283 : {} -> {Right}

[Cobrand]

You're right, there is an error in the display, lines 49 and 50 should be swapped.