wifi: mac80211: mlme: re-parse with correct mode

When doing re-parsing in ieee80211_determine_chan_mode(),
the conn->mode is changed, and the whole point of doing
the parsing again was to parse as the downgraded mode.
However, that didn't actually work, because the setting
was copied before and never changed again. Fix that.

Fixes: 310c8387

 ("wifi: mac80211: clean up connection process")
Reviewed-by: Miriam Rachel Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://msgid.link/20240418105220.5e0d1fcb5622.Ib0673e0bc90033fd6d387b6a5f107c040eb907cf@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>