gallium/util: add casts to silence warnings

src/gallium/auxiliary/pipebuffer/pb_buffer_fenced.c

@@ -540,7 +540,7 @@ fenced_buffer_list_dump(struct fenced_buffer_list *fenced_list)
       fenced_buf = LIST_ENTRY(struct fenced_buffer, curr, head);
       assert(!fenced_buf->fence);
       debug_printf("%10p %7u %7u\n",
-                   fenced_buf,
+                   (void *) fenced_buf,
                    fenced_buf->base.base.size,
                    p_atomic_read(&fenced_buf->base.base.reference.count));
       curr = next; 
@@ -554,10 +554,10 @@ fenced_buffer_list_dump(struct fenced_buffer_list *fenced_list)
       fenced_buf = LIST_ENTRY(struct fenced_buffer, curr, head);
       signaled = ops->fence_signalled(ops, fenced_buf->fence, 0);
       debug_printf("%10p %7u %7u %10p %s\n",
-                   fenced_buf,
+                   (void *) fenced_buf,
                    fenced_buf->base.base.size,
                    p_atomic_read(&fenced_buf->base.base.reference.count),
-                   fenced_buf->fence,
+                   (void *) fenced_buf->fence,
                    signaled == 0 ? "y" : "n");
       curr = next; 
       next = curr->next;