pointer: Remove output position from coordinates

This is no longer required as the input is mapped to the output in the
compositor.

src/pointer.c

@@ -76,8 +76,7 @@ void pointer_set(struct pointer* self, uint32_t x, uint32_t y,
 
 	if (x != self->current_x || y != self->current_y)
 		zwlr_virtual_pointer_v1_motion_absolute(self->pointer, t,
-		                                        self->output->x + x,
-		                                        self->output->y + y,
+		                                        x, y,
 		                                        self->output->width,
 		                                        self->output->height);