LIMS-2078: Fix display of fault reports on visit stats page

[ndg63276]

JIRA ticket: LIMS-2078

Summary:

#979 inadvertently broke the display of fault reports on the visit stats page.

Changes:

• Make sure there is an object to look for s in
• Tidy whitespace

To test:

• Go to a visit stats page for a visit that has a fault report, eg /stats/visit/mx38021-41
• Check the fault report is displayed, and also the "Robot Dewar Usage" chart displays (may take a few seconds)
• Check no errors in the dev console