Fix possible file descriptor leak (fix #485)

common.c

@@ -963,7 +963,6 @@ void write_pid_file(const char* pidfile)
     res = fprintf(f, "%d\n", getpid());
     if (res < 0) {
         print_message(msg_system_error, "write_pid_file: fprintf: %s\n", strerror(errno));
-        return;
     }
 
     res = fclose(f);