benchmark

Remove dead code from PredictNumItersNeeded (#1206)

* Remove `min` with dead path.

When `isSignificant` is false, the smallest value `multiplier` can
approach is 14. Thus, min(10, multiplier) will always return 10.

Addresses part one of #1205.

* Remove always false condition.

   1. `multiplier <= 1.0` implies `i.seconds >= min_time * 1.4`
   2. By (1), `isSignficant` is true because `i.seconds > min_time * 1.4` implies `i.seconds > min_time` implies that `i.seconds / minTime > 1 > 0.1`. Thus, the ternary maintains the same multiplier value.
   3. `ShouldReportResults` is always called before `PredictNumItersNeeded`, if `i.seconds >= min_time` then the loop is broken and `PredictNumItersNeeded` is never called.
   4. 1 and 3 together imply that `multiplier <= 1.0` is never true.

Addresses part 2 of #1205.