userformat_want_item(): mark unused parameter

This function is used as a callback to strbuf_expand(), so it must
conform to the correct interface. But naturally it doesn't need to touch
its "sb" parameter, since it is only examining the placeholder string,
and not actually writing any output. So mark the unused parameter to
silence -Wunused-parameter.

Signed-off-by: Jeff King <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: peff

pretty.c

@@ -1857,7 +1857,8 @@ static size_t format_commit_item(struct strbuf *sb, /* in UTF-8 */
 	return consumed + 1;
 }
 
-static size_t userformat_want_item(struct strbuf *sb, const char *placeholder,
+static size_t userformat_want_item(struct strbuf *sb UNUSED,
+				   const char *placeholder,
 				   void *context)
 {
 	struct userformat_want *w = context;