Force openlog() to open log immediately iff force!=0.
Otherwise is log opened on first syslog() call which may be
after the privileges are dropped and new file descriptors
cannot be created.

Index: vsftpd-3.0.5/sysutil.c
===================================================================
--- vsftpd-3.0.5.orig/sysutil.c	2022-02-01 19:38:36.487789134 +0100
+++ vsftpd-3.0.5/sysutil.c	2022-02-01 19:44:08.787005494 +0100
@@ -2700,7 +2700,7 @@ vsf_sysutil_openlog(int force)
 {
   int facility = LOG_DAEMON;
   int option = LOG_PID;
-  if (!force)
+  if (force)
   {
     option |= LOG_NDELAY;
   }