Fix xargs error in grab_logs

Change-Id: I0d59133e06a8ef629b93356f07c8f90b3f0308cc
diff --git a/tcp_tests/managers/underlay_ssh_manager.py b/tcp_tests/managers/underlay_ssh_manager.py
index 0590e1c..85d5eb5 100644
--- a/tcp_tests/managers/underlay_ssh_manager.py
+++ b/tcp_tests/managers/underlay_ssh_manager.py
@@ -429,11 +429,11 @@
             "docker service ls > "
             "  /root/$(hostname -f)/dump_docker_services_ls.txt;"
             "docker service ls | awk '{ print $2 }' | "
-            "  xargs -I {} docker service ps --no-trunc 2>&1 {} >> "
+            "  xargs -I SERVICE docker service ps --no-trunc 2>&1 SERVICE >> "
             "  /root/$(hostname -f)/dump_docker_service_ps.txt;"
             "docker service ls | awk '{ print $2 }' | "
-            "  xargs -I {} docker service logs 2>&1 {} > "
-            "  /root/$(hostname -f)/dump_docker_service_{}_logs;"
+            "  xargs -I SERVICE docker service logs 2>&1 SERVICE > "
+            "  /root/$(hostname -f)/dump_docker_service_SERVICE_logs;"
             "vgdisplay > /root/$(hostname -f)/dump_vgdisplay.txt;"
             "lvdisplay > /root/$(hostname -f)/dump_lvdisplay.txt;"
             "ip a > /root/$(hostname -f)/dump_ip_a.txt;"