sysmobts: Name the screen and use '-X quit' to shut it down

Use "kill -2 0" for the PCU as SIGTERM is not handled yet. With
the current set of code the stop function will stop both the PCU
and the BTS.

contrib/respawn-only.sh

@@ -3,6 +3,7 @@
 PID=$$
 echo "-1000" > /proc/$PID/oom_score_adj
 
+trap "{ kill 0; kill -2 0; }" EXIT
 
 while [ -f $1 ]; do
 	(echo "0" > /proc/self/oom_score_adj && exec nice -n -20 $*) &

contrib/respawn.sh

@@ -3,6 +3,8 @@
 PID=$$
 echo "-1000" > /proc/$PID/oom_score_adj
 
+trap "kill 0" EXIT
+
 while [ -e /etc/passwd ]; do
 	cat /lib/firmware/sysmobts-v?.bit > /dev/fpgadl_par0
 	sleep 2s

contrib/sysmobts.init

@@ -11,10 +11,10 @@
 
 case "$1" in
         start)
-		/usr/bin/screen -d -m -c /etc/osmocom/screenrc-sysmobts
+		/usr/bin/screen -d -m -c /etc/osmocom/screenrc-sysmobts -S sysmobts
                 ;;
 	stop)
-		echo "This script doesn't support stop"
+		/usr/bin/screen -d -r sysmobts -X quit
                 exit 1
 		;;
         restart|reload|force-reload)