net/mwan3: simplify tracking status statement command

Signed-off-by: Florian Eckert <fe@dev.tdt.de>

net/mwan3/files/lib/mwan3/mwan3.sh

@@ -738,7 +738,7 @@ mwan3_report_iface_status()
 	config_list_foreach $1 track_ip mwan3_list_track_ips
 
 	if [ -n "$track_ips" ]; then
-		if [ -n "$(ps -w | grep mwan3track | grep -v grep | sed '/.*\/usr\/sbin\/mwan3track \([^ ]*\) .*$/!d;s//\1/' | awk '$1 == "'$1'"')" ]; then
+		if [ -n "$(pgrep -f "mwan3track $1")" ]; then
 			tracking="active"
 		else
 			tracking="down"