The only caller of diagnose_invalid_sha1_path() extracts a substring from
an object name by creating a NUL-terminated copy of the interesting part.
Add a length parameter to the function and thus avoid the need for an
allocation, thereby simplifying the code.
Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx> Signed-off-by: Junio C Hamano <gitster@pobox.com>