onepad: drop the pad if an error was detected

v2:
init m_no_error in gamepad constructor

plugins/onepad/GamePad.h

@@ -11,6 +11,7 @@ class GamePad
 public:
     GamePad()
         : m_deadzone(1500)
+        , m_no_error(false)
     {
     }
 
@@ -56,8 +57,14 @@ public:
         return m_deadzone;
     }
 
+    bool IsProperlyInitialized()
+    {
+        return m_no_error;
+    }
+
 protected:
     int m_deadzone;
+    bool m_no_error;
 };
 
 extern std::vector<std::unique_ptr<GamePad>> s_vgamePad;

plugins/onepad/SDL/joystick.cpp

@@ -67,6 +67,9 @@ void JoystickInfo::EnumerateJoysticks(std::vector<std::unique_ptr<GamePad>> &vjo
 
     for (int i = 0; i < SDL_NumJoysticks(); ++i) {
         vjoysticks.push_back(std::unique_ptr<GamePad>(new JoystickInfo(i)));
+        // Something goes wrong in the init, let's drop it
+        if (!vjoysticks.back()->IsProperlyInitialized())
+            vjoysticks.pop_back();
     }
 }
 
@@ -193,6 +196,8 @@ JoystickInfo::JoystickInfo(int id)
 
     fprintf(stdout, "onepad: controller (%s) detected%s, GUID:%s\n",
             devname, m_haptic ? " with rumble support" : "", guid);
+
+    m_no_error = true;
 }
 
 const char *JoystickInfo::GetName()