mac80211: Remove unnecessary variable and label

The variable ret and label just used as return, so we delete it and
use the return statement instead of the goto statement.

Signed-off-by: dingsenjie <dingsenjie@yulong.com>
Link: https://lore.kernel.org/r/20210805064349.202148-1-dingsenjie@163.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>