Update last found time when evaluating an input

[celi0n]

When trying to use the last_found_time member of state, I found that it is only updated in the function add_input.
In my case, I was using fuzzer.fuzz_one and add_input was never called during fuzzing.

This looks like a bug as the description of this field is The last time we found something by ourselves.

In this fix I added 3 lines to update last_found_time when an interesting input is found in evaluate_execution.

[domenukk]

When/why would an interesting input not be added in your case?

[celi0n]

I have no idea, this merge request has nothing to do with how interesting is an input. The code change only update last_found_time which is not used in forkserver_libafl_cc. Maybe it is an issue with the test, or the code I merge from ?

[tokatoka]

lgtm