wifi: mac80211: mlme: remove pointless sta check

We already exited the function if sta ended up NULL,
so just remove the extra check.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230301115906.4cbac9cfd03a.I21ec81c96d246afdabc2b0807d3856e6b1182cb7@changeid


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