io_uring/io-wq: avoid garbage value of 'match' in io_wq_enqueue()

Clang static checker (scan-build) warning:
o_uring/io-wq.c:line 1051, column 3
The expression is an uninitialized value. The computed value will
also be garbage.

'match.nr_pending' is used in io_acct_cancel_pending_work(), but it is
not fully initialized. Change the order of assignment for 'match' to fix
this problem.

Fixes: 42abc95 ("io-wq: decouple work_list protection from the big wqe->lock")
Signed-off-by: Su Hui <suhui@nfschina.com>
Link: https://lore.kernel.org/r/20240604121242.2661244-1-suhui@nfschina.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Author: Su Hui

io_uring/io-wq.c

@@ -927,7 +927,11 @@ void io_wq_enqueue(struct io_wq *wq, struct io_wq_work *work)
 {
 	struct io_wq_acct *acct = io_work_get_acct(wq, work);
 	unsigned long work_flags = work->flags;
-	struct io_cb_cancel_data match;
+	struct io_cb_cancel_data match = {
+		.fn		= io_wq_work_match_item,
+		.data		= work,
+		.cancel_all	= false,
+	};
 	bool do_create;
 
 	/*
@@ -965,10 +969,6 @@ void io_wq_enqueue(struct io_wq *wq, struct io_wq_work *work)
 		raw_spin_unlock(&wq->lock);
 
 		/* fatal condition, failed to create the first worker */
-		match.fn		= io_wq_work_match_item,
-		match.data		= work,
-		match.cancel_all	= false,
-
 		io_acct_cancel_pending_work(wq, acct, &match);
 	}
 }