/*D
   MPI_T_pvar_session_free - Free an existing performance variable session

Synopsis:
.vb
int MPI_T_pvar_session_free(MPI_T_pvar_session *session)
.ve

Input/Output Parameters:
. session - identifier of performance experiment session (handle)

Notes:
Calls to the MPI tool information interface can no longer be made
within the context of a session after it is freed. On a successful
return, MPI sets the session identifier to MPI_T_PVAR_SESSION_NULL.

.N ThreadSafe

.N Errors
.N MPI_SUCCESS
.N MPI_T_ERR_INVALID_SESSION
.N MPI_T_ERR_NOT_INITIALIZED
.N MPI_ERR_OTHER

D*/

