libertas: clean up RSSI command

Convert to a full direct command; previous code rolled a direct
command by hand but left the original indirect command code intact
but disabled.

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 1b9092f..ec41380 100644
--- a/drivers/net/wireless/libertas/cmd.h
+++ b/drivers/net/wireless/libertas/cmd.h
@@ -131,4 +131,6 @@
 
 int lbs_set_monitor_mode(struct lbs_private *priv, int enable);
 
+int lbs_get_rssi(struct lbs_private *priv, s8 *snr, s8 *nf);
+
 #endif /* _LBS_CMD_H */