[$] Best practices for fstests

As a followup to a session on testingchallenges earlier in the day, Josef Bacik led a discussion on bestpractices for testing in a combined storage and filesystem session at the2022 Linux Storage,Filesystem, Memory-management and BPF Summit (LSFMM). There are anumber of ways that developers can collaborate on improving the testinglandscape using fstests and blktests, starting with gathering and sharinginformation about which tests are expected to pass and fail. Thatinformation depends on a lot of different factors, including kernel versionand configuration, fstest options, and more.