adjust fopencookie structure tag for ABI-compat
stdio types use the struct tag names from glibc libio to match C++
ABI.
diff --git a/include/stdio.h b/include/stdio.h
index 2932c76..7c4f9ee 100644
--- a/include/stdio.h
+++ b/include/stdio.h
@@ -188,7 +188,7 @@
typedef int (cookie_seek_function_t)(void *, off_t *, int);
typedef int (cookie_close_function_t)(void *);
-typedef struct {
+typedef struct _IO_cookie_io_functions_t {
cookie_read_function_t *read;
cookie_write_function_t *write;
cookie_seek_function_t *seek;