wifi: brcm80211: Use min() to improve code

Use min() to reduce the code and improve its readability.

Signed-off-by: Qianfeng Rong <rongqianfeng@vivo.com>
Acked-by: Arend van Spriel <arend.vanspriel@broadcom.com&gt;>
Link: https://patch.msgid.link/20250715121721.266713-5-rongqianfeng@vivo.com


Signed-off-by: Johannes Berg <johannes.berg@intel.com>