[MINOR] stick-table: use suffix "_cnt" for cumulated counts

The "_cnt" suffix is already used by ACLs to count various data,
so it makes sense to use the same one in "conn_cnt" instead of
"conn_cum" to count cumulated connections.

This is not a problem because no version was emitted with those
keywords.

Thus we'll try to stick to the following rules :

  xxxx_cnt : cumulated event count for criterion xxxx
  xxxx_cur : current number of concurrent entries for criterion xxxx
  xxxx_rate: event rate for criterion xxxx
diff --git a/src/stick_table.c b/src/stick_table.c
index a5e41bf..9709b73 100644
--- a/src/stick_table.c
+++ b/src/stick_table.c
@@ -525,7 +525,7 @@
 
 /* Extra data types processing */
 struct stktable_data_type stktable_data_types[STKTABLE_DATA_TYPES] = {
-	[STKTABLE_DT_CONN_CUM] = { .name = "conn_cum", .data_length = stktable_data_size(conn_cum) },
+	[STKTABLE_DT_CONN_CNT]  = { .name = "conn_cnt", .data_length = stktable_data_size(conn_cnt) },
 	[STKTABLE_DT_SERVER_ID] = { .name = "server_id", .data_length = stktable_data_size(server_id) },
 };