window.c: Drop timestamp argument to input_set_pointer_image()

We need the serial to set a pointer image and we track that internally.
diff --git a/clients/dnd.c b/clients/dnd.c
index b6720f0..f67bfb5 100644
--- a/clients/dnd.c
+++ b/clients/dnd.c
@@ -423,7 +423,7 @@
 					  dnd_drag->drag_surface,
 					  serial);
 
-		input_set_pointer_image(input, time, CURSOR_DRAGGING);
+		input_set_pointer_image(input, CURSOR_DRAGGING);
 
 		dnd_drag->opaque =
 			create_drag_cursor(dnd_drag, item, x, y, 1);
diff --git a/clients/window.c b/clients/window.c
index 72becab..9472400 100644
--- a/clients/window.c
+++ b/clients/window.c
@@ -1612,7 +1612,7 @@
 		case THEME_LOCATION_TITLEBAR:
 			if (!window->shell_surface)
 				break;
-			input_set_pointer_image(input, time, CURSOR_DRAGGING);
+			input_set_pointer_image(input, CURSOR_DRAGGING);
 			input_ungrab(input);
 			wl_shell_surface_move(window->shell_surface,
 					      input_get_seat(input),
@@ -1729,8 +1729,7 @@
 							widget->user_data);
 		input->focus_widget = focus;
 
-		input_set_pointer_image(input, input->pointer_enter_serial,
-					pointer);
+		input_set_pointer_image(input, pointer);
 	}
 }
 
@@ -1762,7 +1761,7 @@
 						input, time, sx, sy,
 						widget->user_data);
 
-	input_set_pointer_image(input, time, cursor);
+	input_set_pointer_image(input, cursor);
 }
 
 void
@@ -2275,7 +2274,7 @@
 };
 
 void
-input_set_pointer_image(struct input *input, uint32_t time, int pointer)
+input_set_pointer_image(struct input *input, int pointer)
 {
 	struct wl_buffer *buffer;
 	struct wl_cursor *cursor;
@@ -2294,8 +2293,8 @@
 		return;
 
 	input->current_cursor = pointer;
-	wl_pointer_attach(input->pointer, time, buffer,
-			  image->hotspot_x, image->hotspot_y);
+	wl_pointer_attach(input->pointer, input->pointer_enter_serial,
+			  buffer, image->hotspot_x, image->hotspot_y);
 }
 
 struct wl_data_device *
diff --git a/clients/window.h b/clients/window.h
index 1db5eb0..653eaeb 100644
--- a/clients/window.h
+++ b/clients/window.h
@@ -364,7 +364,7 @@
 frame_create(struct window *window, void *data);
 
 void
-input_set_pointer_image(struct input *input, uint32_t time, int pointer);
+input_set_pointer_image(struct input *input, int pointer);
 
 void
 input_get_position(struct input *input, int32_t *x, int32_t *y);