Fix information leak introduced in r1483570. See http://mail-archives.apache.org/mod_mbox/subversion-dev/201502.mbox/%3CCAP_GPNiVRRxt5pL%3DukODSPrs1REjO4VvAhzomFKfcMYYRbvxPQ%40mail.gmail.com%3E * subversion/libsvn_repos/log.c (fill_log_entry): Use the correct method to compare a svn_string_t. Found by: kotkov