Fix videodrv param num, add check xorg.conf existsing.

data/calculate

@@ -8,7 +8,11 @@ depend() {
 
 xorg_video_driver()
 {
-	cat /etc/X11/xorg.conf | grep Driver | cut -d\" -f2
+	local xorgFile="/etc/X11/xorg.conf"
+	if [[ -f $xorgFile ]]
+	then
+		cat /etc/X11/xorg.conf | grep Driver | cut -d\" -f2
+	fi
 }
 
 cmdline_video_driver()
@@ -19,7 +23,7 @@ cmdline_video_driver()
 		case $x in
 			calculate\=*)
 				local value=`echo "$x" | cut -d\= -f2-`
-				local videodrv=`echo "$value" | cut -d, -f4`
+				local videodrv=`echo "$value" | cut -d, -f5`
 				if [[ -n $videodrv ]]
 				then
 					echo "$videodrv"