wifi: rtw89: mcc: prevent shift wrapping in rtw89_core_mlsr_switch()

wifi: rtw89: mcc: prevent shift wrapping in rtw89_core_mlsr_switch()

The "link_id" value comes from the user via debugfs.  If it's larger
than BITS_PER_LONG then that would result in shift wrapping and
potentially an out of bounds access later.  In fact, we can limit it
to IEEE80211_MLD_MAX_NUM_LINKS (15).

Fortunately, only root can write to debugfs files so the security
impact is minimal.

Fixes: 9dd85e739ce0 ("wifi: rtw89: debug: add mlo_mode dbgfs")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Zong-Zhe Yang <kevin_yang@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://patch.msgid.link/aDbFFkX09K7FrL9h@stanley.mountain