libertas: convert CMD_802_11_RADIO_CONTROL to a direct command

and return errors for operations like join & scan that aren't possible
when the radio is turned off.

Signed-off-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/libertas/cmd.h b/drivers/net/wireless/libertas/cmd.h
index 6fba8ef..11ac996 100644
--- a/drivers/net/wireless/libertas/cmd.h
+++ b/drivers/net/wireless/libertas/cmd.h
@@ -65,4 +65,6 @@
 		     s16 *maxlevel);
 int lbs_set_tx_power(struct lbs_private *priv, s16 dbm);
 
+int lbs_set_radio(struct lbs_private *priv, u8 preamble, u8 radio_on);
+
 #endif /* _LBS_CMD_H */