Fix Position not equal operator, add missing cstdint include

This fixes cases where one element doesn't match (0, 1) != (0, 0) fails
and thinks it's equal. This notably affected Wayland scrolling, due to
scrolling mostly being vertical and the backend was checking if the axis
wasn't (0, 0)

Change-Id: I44d52ab683a82900c189e07e62c71cd73c7f8a5c
Reviewed-on: https://codereview.kdab.com/c/kdab/kdutils/+/133341
Tested-by: Continuous Integration <build@kdab.com>
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>

src/KDGui/position.h

@@ -11,6 +11,8 @@
 
 #pragma once
 
+#include <cstdint>
+
 #include <KDGui/kdgui_global.h>
 
 namespace KDGui {
@@ -25,7 +27,7 @@ class KDGUI_API Position
         : x(_x), y(_y) { }
 
     bool operator==(const Position &other) const { return x == other.x && y == other.y; }
-    bool operator!=(const Position &other) const { return x != other.x && y != other.y; }
+    bool operator!=(const Position &other) const { return !(*this == other); }
     Position &operator+=(const Position &other)
     {
         x += other.x;