Fixed a missing typedef.

diff --git a/include/winternl.h b/include/winternl.h
index d5222bc..2a889dc 100644
--- a/include/winternl.h
+++ b/include/winternl.h
@@ -388,7 +388,7 @@
     WCHAR StreamName[1];
 } FILE_STREAM_INFORMATION, *PFILE_STREAM_INFORMATION;
 
-struct _FILE_ATTRIBUTE_TAG_INFORMATION
+typedef struct _FILE_ATTRIBUTE_TAG_INFORMATION
 {
     ULONG FileAttributes;
     ULONG ReparseTag;