X11: Fixed memory leak when initializing multiple screens.

src/video/x11/SDL_x11modes.c

@@ -491,11 +491,11 @@ X11_InitModes_XRandR(_THIS)
                 display.driverdata = displaydata;
                 SDL_AddVideoDisplay(&display);
             }
+
+            X11_XRRFreeScreenResources(res);
         }
     }
 
-    X11_XRRFreeScreenResources(res);
-
     if (_this->num_displays == 0) {
         return SDL_SetError("No available displays");
     }