The condition as it is written in that line has already been checked
in the beginning of the function, which was introduced in 8503ee4 (2007-05-01, Fix read_mailmap to handle a caller uninterested
in repo abbreviation)
Helped-by: Jeff King <peff@peff.net> Helped-by: Thomas Rast <trast@inf.ethz.ch> Signed-off-by: Stefan Beller <stefanbeller@googlemail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>