[OPENMP]Fix PR47621: Variable used by task inside a template function is not...

[OPENMP]Fix PR47621: Variable used by task inside a template function is not made firstprivate by default

Need to fix a check for the variable if it is declared in the inner
OpenMP region to be able to firstprivatize it.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D88240