mpi/src/starpu_mpi.c: free envelope once sent

mpi/src/starpu_mpi.c

@@ -515,6 +515,7 @@ static void _starpu_mpi_irecv_data_func(struct _starpu_mpi_req *req)
 		_STARPU_MPI_COMM_TO_DEBUG(sizeof(struct _starpu_mpi_envelope), MPI_BYTE, req->node_tag.rank, _STARPU_MPI_TAG_ENVELOPE, _STARPU_MPI_TAG_ENVELOPE);
 		req->ret = MPI_Send(_envelope, sizeof(struct _starpu_mpi_envelope), MPI_BYTE, req->node_tag.rank, _STARPU_MPI_TAG_ENVELOPE, req->node_tag.comm);
 		STARPU_MPI_ASSERT_MSG(req->ret == MPI_SUCCESS, "MPI_Send returning %s", _starpu_mpi_get_mpi_code(req->ret));
+		free(envelope);
 	}
 
 	if (req->sync)