[SMPI] Fix headers for call-location tracing.

[SMPI] Fix headers for call-location tracing.

smpi_trace_set_call_location() accesses smpi_process_data(). The data
field however is not initialized until MPI_Init() gets called; hence,
a segfault is caused.

This issue does not exist for the fortran wrappers!

The solution is to initialize the field just before the MPI_Init call.