missed a couple of scalatrace rm's

src/workload/README.nw-workload

-1- The scala-trace-data file has the MPI event data from the phold file for 16 MPI ranks.
-2- The offsets file has the offset from which each LP should start reading from the scala-trace-data file.
-
-3- To run the program with 16 MPI ranks do:
-
-mpirun -np 8 ./codes-nw-test --sync=3 --workload_type=scalatrace --total_nw_lps=16 --offset_file="offsets" --workload_file="scala-trace-data"
-
-The total_nw_lps is equal to the number of MPI ranks on which the data was recorded for scala-trace. In this case,
-total_nw_lps = 16 as the scala-trace data was recorded on 16 MPI ranks.