who: use i64 instead of time_t
who: use i64 instead of time_t

fixes build on raspberry pi 2 (armv7-unknown-linux-gnueabihf)

keunwoo/coreutils,Arcterus/coreutils,keunwoo/coreutils,Arcterus/coreutils,tempbottle/coreutils,jbcrail/coreutils,Heather/coreutils,Heather/coreutils,uutils/coreutils,uutils/coreutils,uutils/coreutils,jbcrail/coreutils,ebfe/coreutils,tempbottle/coreutils,kevgeniy/coreutils,ebfe/coreutils,kevgeniy/coreutils