psasim: small fixes to all.sh and test bash scripts

Signed-off-by: Valerio Setti <valerio.setti@nordicsemi.no>
diff --git a/tests/psa-client-server/psasim/test/run_test.sh b/tests/psa-client-server/psasim/test/run_test.sh
index ac9c4c8..f54e352 100755
--- a/tests/psa-client-server/psasim/test/run_test.sh
+++ b/tests/psa-client-server/psasim/test/run_test.sh
@@ -16,10 +16,9 @@
 CLIENT_BIN=$1
 shift
 
-ipcs | grep q | awk '{ printf " -q " $2 }' | xargs ipcrm > /dev/null 2>&1 || true
+./kill_servers.sh
 
 ./start_server.sh
 ./$CLIENT_BIN "$@"
 
-# Kill server once client exited
-pkill psa_server
+./kill_servers.sh