PDFs not getting picked up in report

[devnoot]

There are some PDFs that are not getting picked up by the Filescan report.

Looking at this course:

https://moodle.swarthmore.edu/course/view.php?id=19701#section-2

The PDF files linked in the Week 2 and Week 3 sections should be picked up, but are not.

[aruethe2]

The filescan does not currently pick up PDFs added to a topic description because the contextlevel is 50 (course) for the topic description instead of 70 (resource).