libertas: fix changing interface type when interface is down

The recent changes to only power the device when the interface up
introduced a bug: changing interface type, legal when the interface
is down, performs device I/O.

Fix this functionality by validating and recording the interface
type when the change is requested, but only applying the change
if/when the interface is brought up.

Signed-off-by: Daniel Drake <dsd@laptop.org>
Acked-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/libertas/decl.h b/drivers/net/wireless/libertas/decl.h
index 9304e6f..bc951ab 100644
--- a/drivers/net/wireless/libertas/decl.h
+++ b/drivers/net/wireless/libertas/decl.h
@@ -9,6 +9,7 @@
 
 #include <linux/netdevice.h>
 #include <linux/firmware.h>
+#include <linux/nl80211.h>
 
 /* Should be terminated by a NULL entry */
 struct lbs_fw_table {
@@ -45,6 +46,7 @@
 
 int lbs_start_iface(struct lbs_private *priv);
 int lbs_stop_iface(struct lbs_private *priv);
+int lbs_set_iface_type(struct lbs_private *priv, enum nl80211_iftype type);
 
 int lbs_rtap_supported(struct lbs_private *priv);