dashboard/app: report that faults were injected

[dvyukov]

From: Steven Rostedt

If you are injecting faults and hitting bugs when you do.

   PLEASE REPORT YOU ARE INJECTING FAULTS!!!

It just happened that I looked at the above console output to know that.
Without that information, this would never be solved, as the memory
failures you are injecting are for things that are less than a page and
would only happen when the system is dangerously low on memory.

Knowing that this was caused after fault injection is critical knowledge!

Without that knowledge, this can be a big waste of time for maintainers who
will go off on wild goose chases trying to figure out what's wrong with the
logic, when it really was simply a missed check of something that didn't
get allocated, that would also never not get allocated unless the system
was in dire straits.

[dvyukov]

Generally there are always some fault injections happened in the past.
How can we understand a past injection is related to bug or not?... We could report injections only in the same process, it may have some false negatives, but may be the best option.

[a-nogikh]

We should also update crash priorities depending on whether we suspect that fault injection was involved (this is similar to what now needs to be done for fsck results).