CPU attempts counted twice

[plasmapower]

CPU attempts counted twice

[PlasmaPower]

That's why I had the - 1 in the gpu progress code! Let's just get rid of this:

nano-vanity/src/main.rs

Lines 140 to 142 in 1d4414e

	if params.output_progress {
	params.attempts.fetch_add(1, atomic::Ordering::Relaxed);
	}

[webmaster128]

:) yes, check_soln is already doing too much suff

[webmaster128]

I just verifierd that the average number of attemtps is 206 % of the expected value after 129 four character runs.