Matrix Converter: fixing issue with deallocation after Kokkos::fininalize()

[lucbv]

Small change but we no longer get an error while running this.

[ndellingwood]

lgtm, simple change like you mentioned (adding scope guards), the extra line changes for the corresponding updated indentation

[lucbv]

Just in case running the spot-check, it went well so let's merge!

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PASSED TESTS
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clang-8.0-Cuda_OpenMP-release build_time=729 run_time=142
clang-8.0-Pthread_Serial-release build_time=248 run_time=133
clang-9.0.0-Pthread-release build_time=163 run_time=62
clang-9.0.0-Serial-release build_time=164 run_time=50
cuda-10.1-Cuda_OpenMP-release build_time=927 run_time=143
cuda-11.0-Cuda_OpenMP-release build_time=937 run_time=141
cuda-9.2-Cuda_Serial-release build_time=894 run_time=223
gcc-7.3.0-OpenMP-release build_time=179 run_time=50
gcc-7.3.0-Pthread-release build_time=147 run_time=70
gcc-8.3.0-Serial-release build_time=171 run_time=58
gcc-9.1-OpenMP-release build_time=236 run_time=50
gcc-9.1-Serial-release build_time=201 run_time=57
intel-17.0.1-Serial-release build_time=430 run_time=54
intel-18.0.5-OpenMP-release build_time=727 run_time=50
intel-19.0.5-Pthread-release build_time=360 run_time=63