dmabuf: annotate dma_buf->active

Contains POLL... bitmaps
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

include/linux/dma-buf.h

@@ -301,7 +301,7 @@ struct dma_buf {
 		struct dma_fence_cb cb;
 		wait_queue_head_t *poll;
 
-		unsigned long active;
+		__poll_t active;
 	} cb_excl, cb_shared;
 };