io_uring/rsrc: zero node's rsrc data on alloc

struct io_rsrc_node::rsrc_data field is initialised on rsrc removal and
shouldn't be used before that, still let's play safe and zero the field
on alloc.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/09bd03cedc8da8a7974c5e6e4bf0489fd16593ab.1681210788.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

io_uring/rsrc.c

@@ -218,6 +218,7 @@ static struct io_rsrc_node *io_rsrc_node_alloc(struct io_ring_ctx *ctx)
 			return NULL;
 	}
 
+	ref_node->rsrc_data = NULL;
 	ref_node->refs = 1;
 	INIT_LIST_HEAD(&ref_node->node);
 	INIT_LIST_HEAD(&ref_node->item_list);