libertas: don't depend on IEEE80211

Runtime-wise we only need escape_ssid from the deprecated IEEE80211
subsystem. However, it's easy to provide our own copy.

Signed-off-by: Holger Schurig <hs4233@mail.mn-solutions.de>
Acked-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/libertas/main.c b/drivers/net/wireless/libertas/main.c
index efff63f..6c2af17 100644
--- a/drivers/net/wireless/libertas/main.c
+++ b/drivers/net/wireless/libertas/main.c
@@ -1559,6 +1559,32 @@
 	return ret;
 }
 
+#ifndef CONFIG_IEEE80211
+const char *escape_essid(const char *essid, u8 essid_len)
+{
+	static char escaped[IW_ESSID_MAX_SIZE * 2 + 1];
+	const char *s = essid;
+	char *d = escaped;
+
+	if (ieee80211_is_empty_essid(essid, essid_len)) {
+		memcpy(escaped, "<hidden>", sizeof("<hidden>"));
+		return escaped;
+	}
+
+	essid_len = min(essid_len, (u8) IW_ESSID_MAX_SIZE);
+	while (essid_len--) {
+		if (*s == '\0') {
+			*d++ = '\\';
+			*d++ = '0';
+			s++;
+		} else {
+			*d++ = *s++;
+		}
+	}
+	*d = '\0';
+	return escaped;
+}
+#endif
 
 module_init(lbs_init_module);
 module_exit(lbs_exit_module);