brcmf_netdev_stop shall first check bus_if status before bringing
down cfg80211. brcmf_detach shall first check if driver is
allocated.
Reviewed-by: Arend Van Spriel <arend@broadcom.com>
Signed-off-by: Hante Meuleman <meuleman@broadcom.com>
Signed-off-by: Franky Lin <frankyl@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>