--dirstat: In case of renames, use target filename instead of source filename

This changes --dirstat analysis to count "damage" toward the target filename,
rather than the source filename. For renames within a directory, this won't
matter to the final output, but when moving files between diretories, the
output now lists the target directory rather than the source directory.

Signed-off-by: Johan Herland <johan@herland.net>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: jherland

diff.c

@@ -1541,7 +1541,7 @@ static void show_dirstat(struct diff_options *options)
 		unsigned long copied, added, damage;
 		int content_changed;
 
-		name = p->one->path ? p->one->path : p->two->path;
+		name = p->two->path ? p->two->path : p->one->path;
 
 		if (p->one->sha1_valid && p->two->sha1_valid)
 			content_changed = hashcmp(p->one->sha1, p->two->sha1);