CMake: Do not touch CMAKE_GENERATOR_TOOLSET

[ruslo]

From documentation:

The value of this variable should never be modified by project code.
... changing the value has undefined behavior.

• https://cmake.org/cmake/help/latest/variable/CMAKE_GENERATOR_TOOLSET.html

Description

Fix CMake configuration error.

Checklist

Essentials

• The problem have been mentioned few times already (e.g. in MXNET-796, Faulty CUDA detection with cmake #12107 (comment)) but all related pull requests are closed at this moment
• Changes are complete (i.e. I finished coding on this PR)

[kalyc]

@lebeg could you take a look at this PR?

[kalyc]

@mxnet-label-bot add [pr-awaiting-merge]

@ruslo thanks for the contribution!

[stu1130]

@mxnet-label-bot update [pr-awaiting-review]
@ruslo Could you check with the CI build failure? feel free to ask questions if you need any help!
@larroy @lebeg ping for the review

[yajiedesign]

yes.it is useless code.
Maybe I didn't explain it clearly.
Reference #9940
The PR also cleaned up this (#10564), but none of them had been merged.

[ruslo]

Could you check with the CI build failure? feel free to ask questions if you need any help!

I'm not sure where is the error.

Makefile:599: recipe for target 'rpkgtest' failed
make: *** [rpkgtest] Error 1

test_model.R:129: error: Fine-tune
cannot open URL 'http://data.dmlc.ml/models/imagenet/inception-bn/Inception-BN-0126.params'
1: GetInception() at R-package/tests/testthat/test_model.R:129
2: download.file("http://data.dmlc.ml/models/imagenet/inception-bn/Inception-BN-0126.params", 
       destfile = "model/Inception-BN-0126.params")

Network problems?

[lebeg]

The failure is unrelated, I've restarted the build.

[stu1130]

@mxnet-label-bot update [pr-awaiting-merge]

[nswamy]

Thanks for your fixing this. merged