Fix "git diff blob1 blob2" showing the diff in reverse.

This was introduced by mistake when revision.c::add_pending_object()
was modified to use object-array instead of object-list.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

builtin-diff.c

@@ -125,9 +125,6 @@ static int builtin_diff_blobs(struct rev_info *revs,
 			      int argc, const char **argv,
 			      struct blobinfo *blob)
 {
-	/* Blobs: the arguments are reversed when setup_revisions()
-	 * picked them up.
-	 */
 	unsigned mode = canon_mode(S_IFREG | 0644);
 
 	if (argc > 1)
@@ -135,7 +132,7 @@ static int builtin_diff_blobs(struct rev_info *revs,
 
 	stuff_change(&revs->diffopt,
 		     mode, mode,
-		     blob[1].sha1, blob[0].sha1,
+		     blob[0].sha1, blob[1].sha1,
 		     blob[0].name, blob[0].name);
 	diffcore_std(&revs->diffopt);
 	diff_flush(&revs->diffopt);