WiFi: fix ieee80211_media_change() callers

WiFi: fix ieee80211_media_change() callers

In r178354 with the introduction of multi-bss ("vap") support factoring
out started and with r193340 ieee80211_media_change() no longer returned
ENETRESET but only 0 or error.
As ieee80211(9) tells the ieee80211_media_change() function should not
be called directly but is registered with ieee80211_vap_attach() instead.

Some drivers have not been fully converted.  After fixing the return
checking some of these functions were simply wrappers between
ieee80211_vap_attach() and ieee80211_media_change(), so remove the extra
function, where possible as well.

PR:		248955
Submitted by:	Tong Zhang (ztong0001 gmail.com) (original)
MFC after:	3 days
Sponsored by:	The FreeBSD Foundation