brcmfmac: start netif queues only when setup is completed successful

Moving the call to netif_start_queue() after brcmf_cfg80211_up() is
completed successful. If not return -EIO instead of -1 as that results
in 'Operation not permitted' which can put user on wrong track.

Reviewed-by: Hante Meuleman <meuleman@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>