Drop hostlen from X509_VERIFY_PARAM_ID.

Just store NUL-terminated strings.  This works better when we add
support for multiple hostnames.

crypto/x509v3/v3_utl.c

@@ -972,6 +972,10 @@ static int do_x509_check(X509 *x, const unsigned char *chk, size_t chklen,
 int X509_check_host(X509 *x, const unsigned char *chk, size_t chklen,
 					unsigned int flags)
 	{
+	if (chklen == 0)
+		chklen = chk ? strlen((char *)chk) : 0;
+	else if (chk && memchr(chk, '\0', chklen))
+		return 0;
 	return do_x509_check(x, chk, chklen, flags, GEN_DNS);
 	}