cfg80211: fix documentation format

Kernel-doc complains if the line isn't prefixed with an
asterisk, fix that.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Link: https://lore.kernel.org/r/20200320144110.2786ad5fb234.I369d103d11c71e39e3a3f97ed68a528c5b875f1e@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/cfg80211.h

@@ -3404,7 +3404,7 @@ struct cfg80211_update_owe_info {
  * @set_default_key: set the default key on an interface
  *
  * @set_default_mgmt_key: set the default management frame key on an interface
-
+ *
  * @set_default_beacon_key: set the default Beacon frame key on an interface
  *
  * @set_rekey_data: give the data necessary for GTK rekeying to the driver