wireless: consolidate on a single escape_essid implementation

Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ipw2200.h b/drivers/net/wireless/ipw2200.h
index 0bad1ec..0a84d52 100644
--- a/drivers/net/wireless/ipw2200.h
+++ b/drivers/net/wireless/ipw2200.h
@@ -48,6 +48,7 @@
 #include <linux/jiffies.h>
 #include <asm/io.h>
 
+#include <net/lib80211.h>
 #include <net/ieee80211.h>
 #include <net/ieee80211_radiotap.h>