Fix potential de-referencing null pointer in SDL_EVDEV_kbd_keycode()

src/core/freebsd/SDL_evdev_kbd_freebsd.c

@@ -476,12 +476,12 @@ void SDL_EVDEV_kbd_keycode(SDL_EVDEV_keyboard_state *kbd, unsigned int keycode,
     unsigned int final_key_state;
     unsigned int map_from_key_sym;
 
-    key_map = *kbd->key_map;
-
     if (kbd == NULL) {
         return;
     }
 
+    key_map = *kbd->key_map;
+
     kbd->rep = (down == 2);
 
     if (keycode < NUM_KEYS) {