We don't get any indication from the stack when we have disassociated.  In
wl1271, it is important to send a CMD_DISCONNECT before joining again,
because the firmware cleans some things up.  So we check if we're already
joined and disconnect if that's the case.
Signed-off-by: NLuciano Coelho <luciano.coelho@nokia.com>
Reviewed-by: NJuuso Oikarinen <juuso.oikarinen@nokia.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>