Cleanup send_nodes_to_accounting().

Continue removing select_g_alter_node_cnt() calls.

The err_cpus return return for:
select_g_select_nodeinfo_get(node_ptr->select_nodeinfo,
                             SELECT_NODEDATA_SUBCNT,
                             NODE_STATE_ERROR, &err_cpus);
is always zero for non-select/bluegene plugins, so this whole
function can be drastically simplified.

Move the node_ptr->name check up front. Invert the remaining logic,
which makes it clear any nodes in DRAIL/FAIL/DOWN are what will
trigger the clusteracct_storage_g_node_down call.