B OpenNebula#4164: Use xmllint to test disk target device (OpenNebula…

…#4168)

Signed-off-by: Anton Todorov <a.todorov@storpool.com>
(cherry picked from commit 4b17b1f)

src/vmm_mad/remotes/kvm/detach_disk

@@ -29,9 +29,10 @@ DETACH_PARAMS="--domain $DOMAIN --target $TARGET"
 exec_and_log "virsh --connect $LIBVIRT_URI detach-disk $DETACH_PARAMS" \
     "Could not detach $TARGET from $DOMAIN"
 
-virsh --connect $LIBVIRT_URI dumpxml $DOMAIN | grep $TARGET > /dev/null 2>&1
+virsh --connect $LIBVIRT_URI dumpxml $DOMAIN | \
+    xmllint -xpath "//disk/target[@dev='$TARGET']" - >/dev/null 2>&1
 
-if [ $? -eq 0 ] ; then
+if [ $? -ne 0 ] ; then
     error_message "Could not detach $TARGET from $DOMAIN"
     exit -1
 fi