unpack_row+binlog_cache_data: fix unused variable

sql/log_cache.h

@@ -237,7 +237,8 @@ class binlog_cache_data
       delete pending();
       set_pending(0);
     }
-    my_bool res= reinit_io_cache(&cache_log, WRITE_CACHE, pos, 0, reset_cache);
+    IF_DBUG(my_bool res=,)
+    reinit_io_cache(&cache_log, WRITE_CACHE, pos, 0, reset_cache);
     DBUG_ASSERT(res == 0);
     cache_log.end_of_file= saved_max_binlog_cache_size;
   }

sql/rpl_record.cc

@@ -439,7 +439,8 @@ int unpack_row(const rpl_group_info *rgi, TABLE *table, uint const colcnt,
     {
       DBUG_ASSERT(bitmap_is_set(cols, i));
       Field *f= conv_table->field[i];
-      bool result= unpack_field(tabledef, f, &st, i);
+      IF_DBUG(bool result=,) 
+      unpack_field(tabledef, f, &st, i);
       DBUG_ASSERT(result);
     }