atftpd: update init script to use procd

* update init script to use procd

Signed-off-by: Mohd Husaam Mehdi <husaam.mehdi@iopsys.eu>

net/atftp/files/atftpd.init

@@ -2,9 +2,11 @@
 # Copyright (C) 2020 OpenWrt.org
 
 START=95
-PIDFILE=/tmp/run/atftpd.pid
 
-start() {
+USE_PROCD=1
+BIN=atftpd
+
+start_service() {
 	local enable
 	local srv
 	local port
@@ -17,9 +19,8 @@ start() {
 	config_get srv service path "/srv/tftp"
 	config_get port service port 69
 
-	atftpd --pidfile $PIDFILE --user root.root --port $port --daemon $srv
-}
-
-stop() {
-	kill $(cat $PIDFILE)
+	procd_open_instance
+	procd_set_param command $BIN "--no-fork" "--daemon" "--user" "root.root" "--port" "$port" "$srv"
+	procd_set_param respawn
+	procd_close_instance
 }