Add a missing pipe in the test from r197896

Spotted by Edward

llvm-svn: 197903
diff --git a/clang/test/Driver/fast-math.c b/clang/test/Driver/fast-math.c
index 16b1efc..690d7a1 100644
--- a/clang/test/Driver/fast-math.c
+++ b/clang/test/Driver/fast-math.c
@@ -8,7 +8,7 @@
 // REQUIRES: clang-driver
 //
 // RUN: %clang -### -fno-honor-infinities -c %s 2>&1 \
-// RUN:   FileCheck --check-prefix=CHECK-NO-INFS %s
+// RUN:   | FileCheck --check-prefix=CHECK-NO-INFS %s
 // infinites [sic] is a supported alternative spelling of infinities.
 // RUN: %clang -### -fno-honor-infinites -c %s 2>&1 \
 // RUN:   | FileCheck --check-prefix=CHECK-NO-INFS %s