Header guard canonicalization, clang part.

Modifications made by clang-tidy with minor tweaks.

llvm-svn: 215557
diff --git a/clang/tools/libclang/CXSourceLocation.h b/clang/tools/libclang/CXSourceLocation.h
index f97ac1f..f0b3f49 100644
--- a/clang/tools/libclang/CXSourceLocation.h
+++ b/clang/tools/libclang/CXSourceLocation.h
@@ -11,8 +11,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef LLVM_CLANG_CXSOURCELOCATION_H
-#define LLVM_CLANG_CXSOURCELOCATION_H
+#ifndef LLVM_CLANG_TOOLS_LIBCLANG_CXSOURCELOCATION_H
+#define LLVM_CLANG_TOOLS_LIBCLANG_CXSOURCELOCATION_H
 
 #include "clang-c/Index.h"
 #include "clang/AST/ASTContext.h"