Why use log() to combine instead of log2()

Line 115 in 29e40b4

const int logbinsize = (int)floor(log(binsize));

Could you please explain the reason for changing log2() to log() ? Given that each of the K hash functions has log2(binsize) bits, is it not correct to shift the hash functions by those number of bits in order to combine them? Wouldn't log2() give a larger value for the shift length, hence increasing the range of the hash function?