LoopControl uses RAND_MAX as the range for random(3)

LoopControl switch from using rand() to using random() for its random numbers when exploring new tile sizes but kept using RAND_MAX to normalize the random number to the range [0,1).

It most likely makes no difference on Linux systems with glibc where (at least on my workstation) RAND_MAX is INT_MAX ie 2^31-1 which is the documented range for random.