Since 3733e69464 (use xmallocz to avoid size arithmetic, 2016-02-22) we
allocate the buffer for the lower case string with xmallocz(). This
already ensures a NUL at the end of the allocated buffer.
Remove the unnecessary assignment.
Signed-off-by: Lars Schneider <larsxschneider@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>