tail: Pre-fill the buffer with zeroes
tail: Pre-fill the buffer with zeroes

Rather than fill the buffer on every file read iteration, pre-fill it with
zeroes once at initialization time.

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