Avoid use-of-uninitialized in i2r_IPAddrBlocks()

Reported by Viktor Szakats in
libressl/portable#910

ok job

lib/libcrypto/x509/x509_addr.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: x509_addr.c,v 1.86 2023/02/16 08:38:17 tb Exp $ */
+/* $OpenBSD: x509_addr.c,v 1.87 2023/09/06 15:32:54 tb Exp $ */
 /*
  * Contributed to the OpenSSL Project by the American Registry for
  * Internet Numbers ("ARIN").
@@ -413,6 +413,13 @@ IPAddressFamily_afi_safi(const IPAddressFamily *af, uint16_t *out_afi,
  uint8_t safi = 0;
  int got_safi = 0;
 
+ if (out_afi != NULL)
+ *out_afi = 0;
+ if (out_safi != NULL) {
+ *out_safi = 0;
+ *safi_is_set = 0;
+ }
+
  CBS_init(&cbs, af->addressFamily->data, af->addressFamily->length);
 
  if (!CBS_get_u16(&cbs, &afi))