add user_data field

quantum/process_keycode/process_tap_dance.h

@@ -44,10 +44,12 @@ typedef struct
 
 #define ACTION_TAP_DANCE_FN(user_fn) {  \
     .fn = { NULL, user_fn, NULL }, \
+    .user_data = NULL, \
   }
 
 #define ACTION_TAP_DANCE_FN_ADVANCED(user_fn_on_each_tap, user_fn_on_dance_finished, user_fn_on_dance_reset) { \
     .fn = { user_fn_on_each_tap, user_fn_on_dance_finished, user_fn_on_dance_reset }, \
+    .user_data = NULL, \
   }
 
 extern qk_tap_dance_action_t tap_dance_actions[];