wl12xx: use a bitmask instead of list of booleans in scanned_ch

We were using an array of booleans to mark the channels we had already
scanned.  This was causing a sparse error, because bool is not a type
with defined size.  To fix this, use bitmasks instead, which is much
cleaner anyway.

Thanks Johannes Berg for the idea.

Signed-off-by: Luciano Coelho <coelho@ti.com>
diff --git a/drivers/net/wireless/wl12xx/wl12xx.h b/drivers/net/wireless/wl12xx/wl12xx.h
index b04481a..ba98e18 100644
--- a/drivers/net/wireless/wl12xx/wl12xx.h
+++ b/drivers/net/wireless/wl12xx/wl12xx.h
@@ -302,9 +302,10 @@
 	u32 addr_extra;
 };
 
+#define WL1271_MAX_CHANNELS 64
 struct wl1271_scan {
 	struct cfg80211_scan_request *req;
-	bool *scanned_ch;
+	unsigned long scanned_ch[BITS_TO_LONGS(WL1271_MAX_CHANNELS)];
 	bool failed;
 	u8 state;
 	u8 ssid[IW_ESSID_MAX_SIZE+1];