diff --no-index: Do not generate patch output if other output is requested

Previously, 'git diff --no-index --stat a b' generated patch output in
addition to the --stat output (or whatever other output format was
requested). Now only the requested output is generated, and patch
output remains the default.
Signed-off-by: NJohannes Sixt <j6t@kdbg.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

diff-no-index.c

@@ -201,8 +201,6 @@ void diff_no_index(struct rev_info *revs,
 		    no_index ? "--no-index" : "[--no-index]");
 
 	diff_setup(&revs->diffopt);
-	if (!revs->diffopt.output_format)
-		revs->diffopt.output_format = DIFF_FORMAT_PATCH;
 	for (i = 1; i < argc - 2; ) {
 		int j;
 		if (!strcmp(argv[i], "--no-index"))
@@ -248,6 +246,8 @@ void diff_no_index(struct rev_info *revs,
 		revs->diffopt.paths = argv + argc - 2;
 	revs->diffopt.nr_paths = 2;
 	revs->diffopt.skip_stat_unmatch = 1;
+	if (!revs->diffopt.output_format)
+		revs->diffopt.output_format = DIFF_FORMAT_PATCH;
 
 	DIFF_OPT_SET(&revs->diffopt, EXIT_WITH_STATUS);
 	DIFF_OPT_SET(&revs->diffopt, NO_INDEX);