libclang: cleanup unused includes in public header

llvm-svn: 188625
diff --git a/clang/tools/libclang/Indexing.cpp b/clang/tools/libclang/Indexing.cpp
index 48fd43b..98395e6 100644
--- a/clang/tools/libclang/Indexing.cpp
+++ b/clang/tools/libclang/Indexing.cpp
@@ -31,6 +31,7 @@
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/Mutex.h"
 #include "llvm/Support/MutexGuard.h"
+#include <stdio.h>
 
 using namespace clang;
 using namespace cxtu;