cfg80211: constify name parameter to add_virtual_intf

The name can't be modified by the driver,
make it const.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/cfg.c

@@ -20,7 +20,8 @@
 #include "rate.h"
 #include "mesh.h"
 
-static struct wireless_dev *ieee80211_add_iface(struct wiphy *wiphy, char *name,
+static struct wireless_dev *ieee80211_add_iface(struct wiphy *wiphy,
+						const char *name,
 						enum nl80211_iftype type,
 						u32 *flags,
 						struct vif_params *params)