note a compile warning that we should investigate one day.

svn:r7052

src/common/crypto.c

@@ -504,6 +504,11 @@ crypto_pk_write_public_key_to_string(crypto_pk_env_t *env, char **dest,
 
   BIO_get_mem_ptr(b, &buf);
   BIO_set_close(b, BIO_NOCLOSE); /* so BIO_free doesn't free buf */
+  /* XXX The above line generates a warning on new gcc/openssls:
+   * crypto.c:506: warning: value computed is not used
+   * Perhaps in new openssls this is a more complex macro and
+   * we're no longer calling it quite right? -RD
+   */
   BIO_free(b);
 
   tor_assert(buf->length >= 0);