Native: fail-safes for simulated node without config file (#3486)

* LinuxInput: only close if file descriptor is assigned

* Native: set some defaults if no configuration file found

src/input/LinuxInput.cpp

@@ -24,7 +24,8 @@ LinuxInput::LinuxInput(const char *name) : concurrency::OSThread(name)
 
 void LinuxInput::deInit()
 {
-    close(fd);
+    if (fd >= 0)
+        close(fd);
 }
 
 int32_t LinuxInput::runOnce()

src/input/LinuxInput.h

@@ -38,7 +38,7 @@ class LinuxInput : public Observable<const InputEvent *>, public concurrency::OS
     int queue_progress = 0;
 
     struct epoll_event events[MAX_EVENTS];
-    int fd;
+    int fd = -1;
     int ret;
     uint8_t report[8];
     int epollfd;