winewayland.drv: Fix the spelling of a comment.

dlls/winewayland.drv/xdg-shell.xml

@@ -620,7 +620,7 @@
       attributes (e.g. title, state, stacking, ...) are discarded for
       an xdg_toplevel surface when it is unmapped. The xdg_toplevel returns to
       the state it had right after xdg_surface.get_toplevel. The client
-      can re-map the toplevel by perfoming a commit without any buffer
+      can re-map the toplevel by performing a commit without any buffer
       attached, waiting for a configure event and handling it as usual (see
       xdg_surface description).