fix compilation with NO_PTHREADS

Commit 1327452 cleaned up an unused parameter from
wait_or_whine, but forgot to update a caller that is inside
"#ifdef NO_PTHREADS".

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/run-command.c b/run-command.c
index 757f263..24eaad5 100644
--- a/run-command.c
+++ b/run-command.c
@@ -725,7 +725,7 @@
 int finish_async(struct async *async)
 {
 #ifdef NO_PTHREADS
-	return wait_or_whine(async->pid, "child process", 0);
+	return wait_or_whine(async->pid, "child process");
 #else
 	void *ret = (void *)(intptr_t)(-1);