compositor: Remove unused wl_pointer variable

Using move_pointer() in notify_pointer_focus() left the wl_pointer variable
unused.
diff --git a/src/compositor.c b/src/compositor.c
index c027578..eb8d473 100644
--- a/src/compositor.c
+++ b/src/compositor.c
@@ -2075,7 +2075,6 @@
 		     wl_fixed_t x, wl_fixed_t y)
 {
 	struct weston_compositor *compositor = seat->compositor;
-	struct wl_pointer *pointer = seat->seat.pointer;
 
 	if (output) {
 		move_pointer(seat, x, y);