Fix builds with RAJA as submodule

[adayton1]

Summary

• This PR is a bugfix
• It does the following:
  • Fixes builds where RAJA is a submodule

[rhornung67]

@adayton1 I'd like someone with more CMake expertise than me to also weigh in on this. I added @davidbeckingsale to review. I can't seem to add Chris.

[adayton1]

This is the error I'm getting in CHAI:

[error]#8 2.837 CMake Error: File /home/chai/workspace/test/CTestCustom.cmake does not exist.

[error]#8 2.837 CMake Error at src/tpl/raja/test/CMakeLists.txt:20 (configure_file):

[error]#8 2.837 configure_file Problem configuring file

[mdavis36]

@rhornung67 FWIW This looks correct to me, we have to use CURRENT in our submodule structure. CMake tries to use the root directory of the "master" project and will not reference the root directory of a given submodule so using the CURRENT variant of these variables is a safer way of doing this.

[rhornung67]

Thank you @mdavis36