Simplify input device destruction code

types/wlr_keyboard.c

@@ -11,11 +11,7 @@ void wlr_keyboard_init(struct wlr_keyboard *kb,
 }
 
 void wlr_keyboard_destroy(struct wlr_keyboard *kb) {
-	if (!kb) {
-		return;
-	}
-	
-	if (kb->impl && kb->impl->destroy) {
+	if (kb && kb->impl && kb->impl->destroy) {
 		kb->impl->destroy(kb);
 	} else {
 		free(kb);

types/wlr_pointer.c

@@ -14,11 +14,7 @@ void wlr_pointer_init(struct wlr_pointer *pointer,
 }
 
 void wlr_pointer_destroy(struct wlr_pointer *pointer) {
-	if (!pointer) {
-		return;
-	}
-	
-	if (pointer->impl && pointer->impl->destroy) {
+	if (pointer && pointer->impl && pointer->impl->destroy) {
 		pointer->impl->destroy(pointer);
 	} else {
 		free(pointer);

types/wlr_touch.c

@@ -14,11 +14,7 @@ void wlr_touch_init(struct wlr_touch *touch,
 }
 
 void wlr_touch_destroy(struct wlr_touch *touch) {
-	if (!touch) {
-		return;
-	}
-	
-	if (touch->impl && touch->impl->destroy) {
+	if (touch && touch->impl && touch->impl->destroy) {
 		touch->impl->destroy(touch);
 	} else {
 		free(touch);