buffer: constify wlr_client_buffer_apply_damage()

include/wlr/types/wlr_buffer.h

@@ -178,6 +178,6 @@ bool wlr_resource_is_buffer(struct wl_resource *resource);
  * isn't mutable.
  */
 bool wlr_client_buffer_apply_damage(struct wlr_client_buffer *client_buffer,
-	struct wlr_buffer *next, pixman_region32_t *damage);
+	struct wlr_buffer *next, const pixman_region32_t *damage);
 
 #endif

types/buffer/client.c

@@ -83,7 +83,7 @@ struct wlr_client_buffer *wlr_client_buffer_create(struct wlr_buffer *buffer,
 }
 
 bool wlr_client_buffer_apply_damage(struct wlr_client_buffer *client_buffer,
-		struct wlr_buffer *next, pixman_region32_t *damage) {
+		struct wlr_buffer *next, const pixman_region32_t *damage) {
 	if (client_buffer->base.n_locks - client_buffer->n_ignore_locks > 1) {
 		// Someone else still has a reference to the buffer
 		return false;