intel openmp always had this treatment of making a separate function for each parallel region. this often seems convenient in accounting separately serial and parallel time. it was extra useful when there was an omp profile option.
parallel_for$omp$parallel_for@?? are functions in OMP library to complete the tasks, which were submitted by parallel_for in user's code. There is no caller-callee relationship, the reason is that parallel_for$omp$parallel_for@?? works in another thread, you should see same behavior when using Intel? Thread Building Block (TBB). Light CPU time is spent in user code, exact work is in parallel library.