wifi: cfg80211: Correct example of ieee80211_iface_limit

Correct wrong closing bracket.

Signed-off-by: Philipp Hortmann <philipp.g.hortmann@gmail.com>
Link: https://lore.kernel.org/r/20221114200135.GA100176@matrix-ESPRIMO-P710


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