[X11] Fixed default cursor (KDE wasn't happy)

src/Avalonia.X11/X11CursorFactory.cs

@@ -14,7 +14,7 @@ namespace Avalonia.X11
         private static readonly Dictionary<StandardCursorType, CursorFontShape> s_mapping =
             new Dictionary<StandardCursorType, CursorFontShape>
             {
-                {StandardCursorType.Arrow, CursorFontShape.XC_arrow},
+                {StandardCursorType.Arrow, CursorFontShape.XC_top_left_arrow},
                 {StandardCursorType.Cross, CursorFontShape.XC_cross},
                 {StandardCursorType.Hand, CursorFontShape.XC_hand1},
                 {StandardCursorType.Help, CursorFontShape.XC_question_arrow},
@@ -50,7 +50,7 @@ namespace Avalonia.X11
         {
             var handle = s_mapping.TryGetValue(cursorType, out var shape)
                 ? _cursors[shape]
-                : _cursors[CursorFontShape.XC_arrow];
+                : _cursors[CursorFontShape.XC_top_left_arrow];
             return new PlatformHandle(handle, "XCURSOR");
         }
     }

src/Avalonia.X11/X11Info.cs

@@ -39,7 +39,7 @@ namespace Avalonia.X11
             DefaultScreen = XDefaultScreen(display);
             BlackPixel = XBlackPixel(display, DefaultScreen);
             RootWindow = XRootWindow(display, DefaultScreen);
-            DefaultCursor = XCreateFontCursor(display, CursorFontShape.XC_arrow);
+            DefaultCursor = XCreateFontCursor(display, CursorFontShape.XC_top_left_arrow);
             DefaultRootWindow = XDefaultRootWindow(display);
             Atoms = new X11Atoms(display);
             //TODO: Open an actual XIM once we get support for preedit in our textbox