weston-log: rename the confusing function name weston_compositor_log_scope_destroy()

There's a function named weston_compositor_log_scope_destroy()
but it doesn't take a struct weston_compositor argument.

Rename it to weston_log_scope_destroy(), as the argument is a
struct weston_log_scope.

Signed-off-by: Leandro Ribeiro <leandrohr@riseup.net>

xwayland/launcher.c

@@ -230,7 +230,7 @@ weston_xserver_destroy(struct wl_listener *l, void *data)
 	if (wxs->loop)
 		weston_xserver_shutdown(wxs);
 
-	weston_compositor_log_scope_destroy(wxs->wm_debug);
+	weston_log_scope_destroy(wxs->wm_debug);
 
 	free(wxs);
 }