Remove __RENAME_STAT64.

Now API level 21 is our lowest supported API level, __RENAME_STAT64 is
useless.

Test: treehugger
Change-Id: I708b2142b30dfcf6c74e1a14475da690a8c25f59
diff --git a/libc/include/ftw.h b/libc/include/ftw.h
index c5fa4de..ee154f0 100644
--- a/libc/include/ftw.h
+++ b/libc/include/ftw.h
@@ -57,8 +57,8 @@
 __BEGIN_DECLS
 int ftw(const char* _Nonnull __dir_path, int (* _Nonnull __callback)(const char* _Nonnull, const struct stat* _Nonnull, int), int __max_fd_count) __INTRODUCED_IN(17);
 int nftw(const char* _Nonnull __dir_path, int (* _Nonnull __callback)(const char* _Nonnull, const struct stat* _Nonnull, int, struct FTW* _Nonnull), int __max_fd_count, int __flags) __INTRODUCED_IN(17);
-int ftw64(const char* _Nonnull __dir_path, int (* _Nonnull __callback)(const char* _Nonnull, const struct stat64* _Nonnull, int), int __max_fd_count) __RENAME_STAT64(ftw, 17, 21);
-int nftw64(const char* _Nonnull __dir_path, int (* _Nonnull __callback)(const char* _Nonnull, const struct stat64* _Nonnull, int, struct FTW* _Nonnull), int __max_fd_count, int __flags) __RENAME_STAT64(nftw, 17, 21);
+int ftw64(const char* _Nonnull __dir_path, int (* _Nonnull __callback)(const char* _Nonnull, const struct stat64* _Nonnull, int), int __max_fd_count) __INTRODUCED_IN(21);
+int nftw64(const char* _Nonnull __dir_path, int (* _Nonnull __callback)(const char* _Nonnull, const struct stat64* _Nonnull, int, struct FTW* _Nonnull), int __max_fd_count, int __flags) __INTRODUCED_IN(21);
 __END_DECLS
 
 #endif