wifi: rtw88: always wait for both firmware loading attempts

In 'rtw_wait_firmware_completion()', always wait for both (regular and
wowlan) firmware loading attempts. Otherwise if 'rtw_usb_intf_init()'
has failed in 'rtw_usb_probe()', 'rtw_usb_disconnect()' may issue
'ieee80211_free_hw()' when one of 'rtw_load_firmware_cb()' (usually
the wowlan one) is still in progress, causing UAF detected by KASAN.

Fixes: c8e5695e ("rtw88: load wowlan firmware if wowlan is supported")
Reported-by:  <syzbot+6c6c08700f9480c41fe3@syzkaller.appspotmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=6c6c08700f9480c41fe3


Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://patch.msgid.link/20240726114657.25396-1-dmantipov@yandex.ru