httpd: free log_file in logger_close()

[Theo Buehler]

The access and error logs are never freed.  They are leaked on sending
USR1 to the parent, for example.

Index: logger.c
===================================================================
RCS file: /cvs/src/usr.sbin/httpd/logger.c,v
retrieving revision 1.22
diff -u -p -r1.22 logger.c
--- logger.c    2 May 2019 22:32:34 -0000       1.22
+++ logger.c    26 Dec 2020 20:36:29 -0000
@@ -89,6 +89,7 @@ logger_close(void)
                        log->log_fd = -1;
                }
                TAILQ_REMOVE(&log_files, log, log_entry);
+               free(log);
        }
 }