UI: keep no-overlap tips open on cursor motion

Was causing flicker.

source/blender/editors/interface/interface_handlers.c

@@ -7822,8 +7822,11 @@ static int ui_handle_button_event(bContext *C, const wmEvent *event, uiBut *but)
 				}
 				else if (event->x != event->prevx || event->y != event->prevy) {
 					/* re-enable tooltip on mouse move */
-					ui_blocks_set_tooltips(ar, true);
-					button_tooltip_timer_reset(C, but);
+					if (!UI_but_is_tooltip_no_overlap(but)) {
+						/* Since this may overlap, close on mouse-move. */
+						ui_blocks_set_tooltips(ar, true);
+						button_tooltip_timer_reset(C, but);
+					}
 				}
 
 				break;