coll-portals4: remove unneeded code from gather

This commit removes two pieces of unneeded code from gather.  First
it removes destroy_tree() calls from linear_top(), because the
linear algorithm does not create a tree, so there is no need to
destroy it.  Second it removes unpack_bytes from the gather request
because it was calculated but never used.

Author: tkordenbrock

ompi/mca/coll/portals4/coll_portals4_gather.c

@@ -177,10 +177,6 @@ setup_gather_buffers_binomial(struct ompi_communicator_t   *comm,
     /* Setup Gather Buffers           */
     /**********************************/
     if (vrank == 0) {
-        request->u.gather.unpack_bytes=
-            request->u.gather.unpack_dst_true_extent +
-            ((ptrdiff_t)request->u.gather.unpack_dst_count * (ptrdiff_t)request->u.gather.size - 1) * request->u.gather.unpack_dst_extent;
-
         request->u.gather.gather_bytes=request->u.gather.packed_size * (ptrdiff_t)request->u.gather.size;
 
         /*
@@ -282,10 +278,6 @@ setup_gather_buffers_linear(struct ompi_communicator_t   *comm,
     /* Setup Gather Buffers           */
     /**********************************/
     if (i_am_root) {
-        request->u.gather.unpack_bytes=
-            request->u.gather.unpack_dst_true_extent +
-            ((ptrdiff_t)request->u.gather.unpack_dst_count * (ptrdiff_t)request->u.gather.size - 1) * request->u.gather.unpack_dst_extent;
-
         request->u.gather.gather_bytes=request->u.gather.packed_size * (ptrdiff_t)request->u.gather.size;
 
         /*
@@ -1005,8 +997,6 @@ ompi_coll_portals4_gather_intra_linear_top(const void *sbuf, int scount, struct
                 "completed CTWait(expected_ops=%d)\n", expected_ops);
     }
 
-    ompi_coll_portals4_destroy_tree(&(portals4_module->cached_in_order_bmtree));
-
     OPAL_OUTPUT((ompi_coll_base_framework.framework_output,
                  "coll:portals4:gather_intra_linear_top exit rank %d", request->u.gather.my_rank));
 
@@ -1016,8 +1006,6 @@ ompi_coll_portals4_gather_intra_linear_top(const void *sbuf, int scount, struct
     if (NULL != request->u.gather.gather_buf)
         free(request->u.gather.gather_buf);
 
-    ompi_coll_portals4_destroy_tree(&(portals4_module->cached_in_order_bmtree));
-
     opal_output(ompi_coll_base_framework.framework_output,
                 "%s:%4d:%4d\tError occurred ret=%d, rank %2d",
                 __FILE__, __LINE__, line, ret, request->u.gather.my_rank);

ompi/mca/coll/portals4/coll_portals4_request.h

@@ -114,7 +114,6 @@ struct ompi_coll_portals4_request_t {
             MPI_Aint                pack_src_lb;
             MPI_Aint                pack_src_true_lb;
             MPI_Aint                pack_src_offset;
-            uint64_t                unpack_bytes;
             char                   *unpack_dst_buf;
             int                     unpack_dst_count;
             struct ompi_datatype_t *unpack_dst_dtype;