Fix a possible recursion in SSLfatal handling

Fixes: #7161 (hopefully)
Reviewed-by: NMatt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/7175)

(cherry picked from commit 6839a7a7f4973a3fc2f87b12664c26d524bef1f4)

ssl/statem/statem.c

@@ -118,11 +118,12 @@ void ossl_statem_set_renegotiate(SSL *s)
 void ossl_statem_fatal(SSL *s, int al, int func, int reason, const char *file,
                        int line)
 {
+    ERR_put_error(ERR_LIB_SSL, func, reason, file, line);
     /* We shouldn't call SSLfatal() twice. Once is enough */
-    assert(s->statem.state != MSG_FLOW_ERROR);
+    if (s->statem.in_init && s->statem.state == MSG_FLOW_ERROR)
+      return;
     s->statem.in_init = 1;
     s->statem.state = MSG_FLOW_ERROR;
-    ERR_put_error(ERR_LIB_SSL, func, reason, file, line);
     if (al != SSL_AD_NO_ALERT
             && s->statem.enc_write_state != ENC_WRITE_STATE_INVALID)
         ssl3_send_alert(s, SSL3_AL_FATAL, al);