Minor optimization in generation of exponential distribution from uniform
Minor optimization in generation of exponential distribution from uniform

Summary:
Instead of "exp = - ln(1 - uniform) * mean"
one can do "exp = - ln(uniform) * mean"
which is equivalent
Closes https://github.com/facebook/treadmill/pull/10

Reviewed By: lpkruger

Differential Revision: D3594092

Pulled By: meisner

fbshipit-source-id: 0a49763bde5fb2369df16278341b25406ae347cf

yqzhang/treadmill,yqzhang/treadmill