Rename int_*() functions to *_int()

There is a preference for suffixes to indicate that a function is internal
rather than prefixes. Note: the suffix is only required to disambiguate
internal functions and public symbols with the same name (but different
case)

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>

include/internal/bio.h

@@ -67,4 +67,4 @@ struct bio_method_st {
     long (*callback_ctrl) (BIO *, int, bio_info_cb *);
 };
 
-void int_bio_sock_cleanup(void);
+void bio_sock_cleanup_int(void);