Fix cleanup-containers

qemu-ga should be excluded

Change-Id: I89474758a45e52c6c2da7307764344863e065aed
Closes-Bug: #1655838

tools/cleanup-containers

 #!/bin/bash
-QEMU_PIDS=$(pgrep qemu)
+QEMU_PIDS=$(pgrep -l qemu | awk '!/qemu-ga/ {print $1}')
 if [[ $COMPUTE ]] && [[ $QEMU_PIDS ]] && [[ $(ps --no-headers wwwup $QEMU_PIDS | grep --invert-match '\-xen\-domid 0') ]]; then
     echo "Some qemu processes were detected."
     echo "Docker will not be able to stop the nova_libvirt container with those running."