cfg80211: fix a few kernel-doc warnings

Fix multiple kernel-doc warnings in cfg80211.h.

cfg80211.h:363: warning: missing initial short description on line:
 * struct ieee80211_sband_iftype_data
cfg80211.h:6743: warning: missing initial short description on line:
 * cfg80211_vendor_cmd_get_sender
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20210417060142.1648-1-rdunlap@infradead.orgSigned-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/cfg80211.h

@@ -360,7 +360,7 @@ struct ieee80211_sta_he_cap {
 };
 
 /**
- * struct ieee80211_sband_iftype_data
+ * struct ieee80211_sband_iftype_data - sband data per interface type
  *
  * This structure encapsulates sband data that is relevant for the
  * interface types defined in @types_mask.  Each type in the
@@ -6740,7 +6740,7 @@ cfg80211_vendor_cmd_alloc_reply_skb(struct wiphy *wiphy, int approxlen)
 int cfg80211_vendor_cmd_reply(struct sk_buff *skb);
 
 /**
- * cfg80211_vendor_cmd_get_sender
+ * cfg80211_vendor_cmd_get_sender - get the current sender netlink ID
  * @wiphy: the wiphy
  *
  * Return the current netlink port ID in a vendor command handler.