wifi: rtw89: add bounds check on firmware mac_id in link lookup

wifi: rtw89: add bounds check on firmware mac_id in link lookup

The mac_id field in RX descriptors is 8 bits wide (0-255), but
assoc_link_on_macid[] has only RTW89_MAX_MAC_ID_NUM (128) entries.
While the driver currently assigns mac_id values below 128, the
descriptor value comes from firmware and is not validated before use
as an array index. Add a defensive bounds check in
rtw89_assoc_link_rcu_dereference() to guard against out-of-range
firmware values.

Fixes: 144c6cd24b35 ("wifi: rtw89: 8922a: configure AP_LINK_PS if FW supports")
Signed-off-by: Tristan Madani <tristan@talencesecurity.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://patch.msgid.link/20260421111442.3395411-1-tristmd@gmail.com