tag.c: Correct indentation

These lines were incorrectly indented with spaces, violating our
coding style.  Its annoying to read with 4 position tab stops, so
fix the indentation to be correct.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

tag.c

@@ -44,9 +44,9 @@ int parse_tag_buffer(struct tag *item, void *data, unsigned long size)
 	char type[20];
 	const char *start = data;
 
-        if (item->object.parsed)
-                return 0;
-        item->object.parsed = 1;
+	if (item->object.parsed)
+		return 0;
+	item->object.parsed = 1;
 
 	if (size < 64)
 		return -1;