[PATCH] libertas: fix "warning: Using plain integer as NULL pointer" sparse warnings

This fixes three "warning: Using plain integer as NULL pointer"
sparse warnings.
Signed-off-by: Holger Schurig <hs4233@mail.mn-solutions.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/libertas/scan.c

@@ -578,7 +578,7 @@ static int wlan_scan_channel_list(wlan_private * priv,
 
 	lbs_deb_enter(LBS_DEB_ASSOC);
 
-	if (pscancfgout == 0 || pchantlvout == 0 || pscanchanlist == 0) {
+	if (!pscancfgout || !pchantlvout || !pscanchanlist) {
 		lbs_deb_scan("Scan: Null detect: %p, %p, %p\n",
 		       pscancfgout, pchantlvout, pscanchanlist);
 		return -1;