few rgi assertions. this can proof that rgi is always present

sql/log_event_server.cc

@@ -4741,6 +4741,7 @@ inline void restore_empty_query_table_list(LEX *lex)
 
 int Rows_log_event::do_apply_event(rpl_group_info *rgi)
 {
+  DBUG_ASSERT(rgi);
   Relay_log_info const *rli= rgi->rli;
   TABLE* table;
   DBUG_ENTER("Rows_log_event::do_apply_event(Relay_log_info*)");
@@ -5062,7 +5063,7 @@ int Rows_log_event::do_apply_event(rpl_group_info *rgi)
       set_flags(COMPLETE_ROWS_F);
 
     Rpl_table_data rpl_data{};
-    if (rgi) rgi->get_table_data(table, &rpl_data);
+    rgi->get_table_data(table, &rpl_data);
 
     /* 
       Set tables write and read sets.

sql/rpl_record.cc

@@ -165,7 +165,7 @@ pack_row(TABLE *table, MY_BITMAP const* cols,
    unpack a row from from the backup image, but can be used for other
    purposes as well.
 
-   @param rli     Relay log info, which can be NULL
+   @param rgi     Relay group info
    @param table   Table to unpack into
    @param colcnt  Number of columns to read from record
    @param row_data
@@ -231,6 +231,7 @@ int unpack_row(rpl_group_info *rgi, TABLE *table, uint const colcnt,
                        table_found, tabledef, conv_table));
   DBUG_ASSERT(table_found);
 
+  DBUG_ASSERT(rgi);
   /*
     If rgi is NULL it means that there is no source table and that the
     row shall just be unpacked without doing any checks. This feature