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>

crypto/include/internal/rand.h

@@ -8,4 +8,4 @@
 
 #include <openssl/rand.h>
 
-void int_rand_cleanup(void);
+void rand_cleanup_int(void);