Allow $ntpdate_config to be NULL. Due to a lack of surrounding quotes, when

ntpdate_config was set to NULL the conditional would (counter to prevailing
logic) succeed -- leading to awk attempting to redirect from a NULL pathname
standard-in. While we're here, make the script consistant with itself by
removing the {curlies} around ntpdate_config (they are unnecessary).

etc/rc.d/ntpdate

@@ -16,13 +16,13 @@ start_cmd="ntpdate_start"
 
 ntpdate_start()
 {
-	if [ -z "$ntpdate_hosts" -a -f ${ntpdate_config} ]; then
+	if [ -z "$ntpdate_hosts" -a -f "$ntpdate_config" ]; then
 		ntpdate_hosts=`awk '
 			/^server[ \t]*127.127/      {next}
 			/^(server|peer)/            {
 			    if ($2 ~/^-/)           {print $3}
 			    else                    {print $2}}
-		' < ${ntpdate_config}`
+		' < "$ntpdate_config"`
 	fi
 	if [ -n "$ntpdate_hosts" -o -n "$rc_flags" ]; then
 		echo "Setting date via ntp."