wifi: rtw89: usb: use common error path for skbs in rtw89_usb_rx_handler()

wifi: rtw89: usb: use common error path for skbs in rtw89_usb_rx_handler()

Allow adding rx_skb to rx_free_queue for later reuse on the common error
handling path, otherwise free it.

Found by Linux Verification Center (linuxtesting.org).

Fixes: 2135c28be6a8 ("wifi: rtw89: Add usb.{c,h}")
Acked-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://patch.msgid.link/20251104135720.321110-2-pchelkin@ispras.ru