midx: honor the MIDX_PROGRESS flag in midx_repack

Update midx_repack to only display progress when
the MIDX_PROGRESS flag is set.

Signed-off-by: William Baker <William.Baker@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/midx.c b/midx.c
index 1b22b21..37ec286 100644
--- a/midx.c
+++ b/midx.c
@@ -1373,6 +1373,12 @@ int midx_repack(struct repository *r, const char *object_dir, size_t batch_size,
 	strbuf_addstr(&base_name, object_dir);
 	strbuf_addstr(&base_name, "/pack/pack");
 	argv_array_push(&cmd.args, base_name.buf);
+
+	if (flags & MIDX_PROGRESS)
+		argv_array_push(&cmd.args, "--progress");
+	else
+		argv_array_push(&cmd.args, "-q");
+
 	strbuf_release(&base_name);
 
 	cmd.git_cmd = 1;