MXS-1346: Take the new query classifier features into use

The function usage by column is now used by the dbfwfilter. This finishes
the implementation of blocking function usage per column.

server/modules/filter/dbfwfilter/dbfwfilter.c

@@ -2166,7 +2166,9 @@ void match_function_usage(RULE *rule, GWBUF *queue, enum fw_actions mode,
 
     for (size_t i = 0; i < n_infos; ++i)
     {
-        const char* tok = "TODO: Use the actual function values";
+        for (size_t j = 0; j < infos[i].n_fields; j++)
+        {
+            const char* tok = infos[i].fields[j].column;
 
             for (STRLINK* s = (STRLINK*)rule->data; s; s = s->next)
             {
@@ -2180,6 +2182,7 @@ void match_function_usage(RULE *rule, GWBUF *queue, enum fw_actions mode,
                 }
             }
         }
+    }
 }
 
 void match_wildcard(RULE_BOOK *rulebook, GWBUF *queue, bool *matches, char **msg)