smtp: log transaction even if no email present

The SMTP transaction logger was not writing the log if the email
portion of the logger failed, such as in the case of STARTTLS
where this is no email decoded.

Ticket #4817

(cherry picked from commit 52b9c12f41)

src/output-json-smtp.c

@@ -88,9 +88,8 @@ static int JsonSmtpLogger(ThreadVars *tv, void *thread_data, const Packet *p, Fl
     EveSmtpDataLogger(f, state, tx, tx_id, jb);
     jb_close(jb);
 
-    if (EveEmailLogJson(jhl, jb, p, f, state, tx, tx_id) == TM_ECODE_OK) {
-        OutputJsonBuilderBuffer(jb, jhl->file_ctx, &jhl->buffer);
-    }
+    EveEmailLogJson(jhl, jb, p, f, state, tx, tx_id);
+    OutputJsonBuilderBuffer(jb, jhl->file_ctx, &jhl->buffer);
 
     jb_free(jb);