wifi: cfg80211: fix two more possible UBSAN-detected off-by-one errors

wifi: cfg80211: fix two more possible UBSAN-detected off-by-one errors

Although not reproduced in practice, these two cases may be
considered by UBSAN as off-by-one errors. So fix them in the
same way as in commit a26a5107bc52 ("wifi: cfg80211: fix UBSAN
noise in cfg80211_wext_siwscan()").

Fixes: 807f8a8c3004 ("cfg80211/nl80211: add support for scheduled scans")
Fixes: 5ba63533bbf6 ("cfg80211: fix alignment problem in scan request")
Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Link: https://patch.msgid.link/20240909090806.1091956-1-dmantipov@yandex.ru
Signed-off-by: Johannes Berg <johannes.berg@intel.com>