[fix] Indexing.cu: Move call to C10_CUDA_KERNEL_LAUNCH_CHECK to make it reachable (#49283)
Summary:
Fixes Compiler Warning:
```
aten/src/ATen/native/cuda/Indexing.cu(233): warning: loop is not reachable
aten/src/ATen/native/cuda/Indexing.cu(233): warning: loop is not reachable
aten/src/ATen/native/cuda/Indexing.cu(233): warning: loop is not reachable
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/49283
Reviewed By: zhangguanheng66
Differential Revision: D25874613
Pulled By: ngimel
fbshipit-source-id: 6e384e89533c1d80f241b7b98fda239c357d1a2c