wifi: mac80211: fix unsolicited broadcast probe config

There's a bug in ieee80211_set_unsol_bcast_probe_resp(), it tries
to return BSS_CHANGED_UNSOL_BCAST_PROBE_RESP (which has the value
1<<31) in an int, which makes it negative and considered an error.
Fix this by passing the changed flags to set separately.

Fixes: 3b1c256e

 ("wifi: mac80211: fixes in FILS discovery updates")
Reviewed-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Link: https://msgid.link/20240129195729.965b0740bf80.I6bc6f5236863f686c17d689be541b1dd2633c417@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>