wifi: mac80211: fix userspace_selectors corruption

Spotted during code review, the selectors need to be large
enough for a 128-bit bitmap, not a single unsigned long,
otherwise we have stack corruption.

We should also allow passing selectors from userspace, but
that should be a separate change.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Ilan Peer <ilan.peer@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://patch.msgid.link/20250308225541.8f1bcf96a504.Ibeb8970c82a30c97279a4cc4e68faca5df1813a5@changeid


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