[PATCH] ieee80211: fix sparse warning about missing "static"

This patch adds a missing "static" on a variable (sparse complaint)
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/ieee80211/ieee80211_module.c

@@ -213,7 +213,7 @@ void free_ieee80211(struct net_device *dev)
 
 static int debug = 0;
 u32 ieee80211_debug_level = 0;
-struct proc_dir_entry *ieee80211_proc = NULL;
+static struct proc_dir_entry *ieee80211_proc = NULL;
 
 static int show_debug_level(char *page, char **start, off_t offset,
 			    int count, int *eof, void *data)