Fix typo.

llvm-svn: 161106

clang/test/Tooling/pch.cpp

@@ -5,7 +5,7 @@
 // a stat cache into the FileManager:
 // RUN: %clang -x c++-header %S/Inputs/pch.h -o %t1
 
-// Use the generated pch and enforce a subsequent stat miss by by using
+// Use the generated pch and enforce a subsequent stat miss by using
 // the test file with an unrelated include as second translation unit:
 // Do not directly pipe into FileCheck, as that would hide errors from
 // valgrind due to pipefail not being set in lit.