silence log output for unknown input

src/core/linux/SDL_evdev.c

@@ -396,11 +396,13 @@ SDL_EVDEV_translate_keycode(int keycode)
     if (keycode < SDL_arraysize(linux_scancode_table))
         scancode = linux_scancode_table[keycode];
 
+    /*
     if (scancode == SDL_SCANCODE_UNKNOWN) {
         SDL_Log("The key you just pressed is not recognized by SDL. To help "
             "get this fixed, please report this to the SDL forums/mailing list "
             "<https://discourse.libsdl.org/> EVDEV KeyCode %d", keycode);
     }
+    */
 
     return scancode;
 }