seat/keyboard: drop unnecessary check in handle_keyboard_keymap()

This condition always holds true: the listener is set up for
state->keyboard.

types/seat/wlr_seat_keyboard.c

@@ -89,12 +89,9 @@ static void handle_keyboard_keymap(struct wl_listener *listener, void *data) {
 	struct wlr_seat_keyboard_state *state =
 		wl_container_of(listener, state, keyboard_keymap);
 	struct wlr_seat_client *client;
-	struct wlr_keyboard *keyboard = data;
-	if (keyboard == state->keyboard) {
 	wl_list_for_each(client, &state->seat->clients, link) {
 		seat_client_send_keymap(client, state->keyboard);
 	}
-	}
 }
 
 static void seat_client_send_repeat_info(struct wlr_seat_client *client,