mac80211: dont program keys for stations not uploaded

If a station couldn't be uploaded to the driver but
is still kept (only in IBSS mode) we still shouldn't
try to program the keys for it into hardware; fix
this bug by skipping the key upload in this case.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>