uucore::utmpx: refine implementation
uucore::utmpx: refine implementation

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