Fix the run line for this test.

llvm-svn: 52169
diff --git a/clang/test/Lexer/digraph.c b/clang/test/Lexer/digraph.c
index 07c085a..9683ee4 100644
--- a/clang/test/Lexer/digraph.c
+++ b/clang/test/Lexer/digraph.c
@@ -1,4 +1,4 @@
-// RUN: clang -fsyntax-only %s
+// RUN: clang -fsyntax-only -verify < %s
 
 %:include <stdio.h>