rsi: stop thread firstly in rsi_91x_init() error handling

When fail to init coex module, free 'common' and 'adapter' directly, but
common->tx_thread which will access 'common' and 'adapter' is running at
the same time. That will trigger the UAF bug.

==================================================================
BUG: KASAN: use-after-free in rsi_tx_scheduler_thread+0x50f/0x520 [rsi_91x]
Read of size 8 at addr ffff8880076dc000 by task Tx-Thread/124777
CPU: 0 PID: 124777 Comm: Tx-Thread Not tainted 5.15.0-rc5+ #19
Call Trace:
 dump_stack_lvl+0xe2/0x152
 print_address_description.constprop.0+0x21/0x140
 ? rsi_tx_scheduler_thread+0x50f/0x520
 kasan_report.cold+0x7f/0x11b
 ? rsi_tx_scheduler_thread+0x50f/0x520
 rsi_tx_scheduler_thread+0x50f/0x520
...

Freed by task 111873:
 kasan_save_stack+0x1b/0x40
 kasan_set_track+0x1c/0x30
 kasan_set_free_info+0x20/0x30
 __kasan_slab_free+0x109/0x140
 kfree+0x117/0x4c0
 rsi_91x_init+0x741/0x8a0 [rsi_91x]
 rsi_probe+0x9f/0x1750 [rsi_usb]

Stop thread before free 'common' and 'adapter' to fix it.

Fixes: 2108df3 ("rsi: add coex support")
Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20211015040335.1021546-1-william.xuanziyang@huawei.com

drivers/net/wireless/rsi/rsi_91x_main.c

@@ -369,6 +369,7 @@ struct rsi_hw *rsi_91x_init(u16 oper_mode)
 	if (common->coex_mode > 1) {
 		if (rsi_coex_attach(common)) {
 			rsi_dbg(ERR_ZONE, "Failed to init coex module\n");
+			rsi_kill_thread(&common->tx_thread);
 			goto err;
 		}
 	}