Fix interval midpoint calculation in vulkan (#46839)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/46839
Interval midpoint calculations can overflow (integers). This fixes such an instance.
Test Plan: Standard test rig.
Reviewed By: drdarshan
Differential Revision: D24392545
fbshipit-source-id: 84c81802165bb8084e2d54c9f3755f39143a5b00
