* dk/blame-janitorial:
builtin/blame.c::find_copy_in_blob: no need to scan for region end
blame.c: prepare_lines should not call xrealloc for every line
builtin/blame.c::prepare_lines: fix allocation size of sb->lineno
builtin/blame.c: eliminate same_suspect()
builtin/blame.c: struct blame_entry does not need a prev link