mac80211: Fix scan_ies_len to include DS Params

Commit 651b52254fc061f02d965524e71de4333a009a5a added DS Parameter Set
information into Probe Request frames that are transmitted on 2.4 GHz
band, but it failed to increment local->scan_ies_len to cover this new
information. This variable needs to be updated to match the maximum IE
data length so that the extra buffer need gets reduced from the driver
limit.

Signed-off-by: Jouni Malinen <j@w1.fi>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/mac80211/main.c

@@ -677,10 +677,11 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
 	/*
 	 * Calculate scan IE length -- we need this to alloc
 	 * memory and to subtract from the driver limit. It
-	 * includes the (extended) supported rates and HT
+	 * includes the DS Params, (extended) supported rates, and HT
 	 * information -- SSID is the driver's responsibility.
 	 */
-	local->scan_ies_len = 4 + max_bitrates; /* (ext) supp rates */
+	local->scan_ies_len = 4 + max_bitrates /* (ext) supp rates */ +
+		3 /* DS Params */;
 	if (supp_ht)
 		local->scan_ies_len += 2 + sizeof(struct ieee80211_ht_cap);