Fix include guards so they exactly match file names.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172025 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm-c/lto.h b/include/llvm-c/lto.h
index 74915c0..40110fd 100644
--- a/include/llvm-c/lto.h
+++ b/include/llvm-c/lto.h
@@ -13,8 +13,8 @@
 |*                                                                            *|
 \*===----------------------------------------------------------------------===*/
 
-#ifndef LTO_H
-#define LTO_H  1
+#ifndef LLVM_C_LTO_H
+#define LLVM_C_LTO_H
 
 #include <stdbool.h>
 #include <stddef.h>