Add some retries to try to work around transient failures

Change-Id: I000decebfdafd66aed1a1e0620eb926772905af4
(cherry picked from commit 66ee90186ba604c95fbb61144adf31e1ddd194f7)
diff --git a/roles/cloudlab-prep/tasks/main.yml b/roles/cloudlab-prep/tasks/main.yml
index 5bf71a3..f66e94d 100644
--- a/roles/cloudlab-prep/tasks/main.yml
+++ b/roles/cloudlab-prep/tasks/main.yml
@@ -13,4 +13,8 @@
   command: /usr/testbed/bin/mkextrafs -r {{ item.dev }} -qf {{ item.mount }}
     creates={{ item.mount }}/lost+found
   with_items: "{{ cloudlab_extrafs }}"
+  register: result
+  until: result | success
+  retries: 3
+  delay: 5