Make failures in find_analysis non-fatal.
Make failures in find_analysis non-fatal.

The indexer is currently failing in the IPDL analysis step due to
failing to find a symbol. I'm not sure why that is not working, so
instead this patch makes it so that we don't output anything in that
case. We've lived this long without IPDL indexing working correctly.

bill-mccloskey/searchfox,bill-mccloskey/mozsearch,bill-mccloskey/mozsearch,bill-mccloskey/mozsearch,bill-mccloskey/searchfox,bill-mccloskey/mozsearch,bill-mccloskey/mozsearch,bill-mccloskey/searchfox,bill-mccloskey/searchfox,bill-mccloskey/searchfox,bill-mccloskey/searchfox,bill-mccloskey/mozsearch