[t:4618], fix regression introduced by fix for 4648

git-svn-id: file:///svn/mysql/tokudb-engine/tokudb-engine@41307 c7de825b-a66e-492c-adef-691d508d4ae1

storage/tokudb/ha_tokudb.cc

@@ -4048,13 +4048,8 @@ int ha_tokudb::update_row(const uchar * old_row, uchar * new_row) {
     } 
     else {
         create_dbt_key_from_table(&prim_key, primary_key, key_buff, new_row, &has_null);
-        if (key_changed(primary_key, old_row, new_row)) {
         create_dbt_key_from_table(&old_prim_key, primary_key, primary_key_buff, old_row, &has_null);
     }
-        else {
-            old_prim_key = prim_key;
-        }
-    }
 
     //
     // do uniqueness checks