wifi: mac80211: remove ieee80211_link_unreserve_chanctx() return value

wifi: mac80211: remove ieee80211_link_unreserve_chanctx() return value

All the paths that could return an error are considered
misuses of the function and WARN already, and none of
the callers ever check the return value. Remove it.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://patch.msgid.link/20250709233537.5b436ee3c20c.Ieff61ec510939adb5fe6da4840557b649b3aa820@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>