making perfschema easier to merge: remove unnecessary changes

storage/perfschema/ha_perfschema.cc

@@ -392,6 +392,11 @@ int ha_perfschema::delete_all_rows(void)
   DBUG_RETURN(result);
 }
 
+int ha_perfschema::truncate()
+{
+  return delete_all_rows();
+}
+
 THR_LOCK_DATA **ha_perfschema::store_lock(THD *thd,
                                        THR_LOCK_DATA **to,
                                        enum thr_lock_type lock_type)

storage/perfschema/ha_perfschema.h

@@ -69,8 +69,8 @@ public:
       calls ::rnd_pos(), so it is guaranteed to return only thread <n>
       records.
     */
-    return (HA_NO_TRANSACTIONS | HA_REC_NOT_IN_SEQ | HA_NO_AUTO_INCREMENT |
-            HA_PRIMARY_KEY_REQUIRED_FOR_DELETE);
+    return HA_NO_TRANSACTIONS | HA_REC_NOT_IN_SEQ | HA_NO_AUTO_INCREMENT |
+      HA_PRIMARY_KEY_REQUIRED_FOR_DELETE;
   }
 
   /**
@@ -170,6 +170,8 @@ public:
 
   int delete_all_rows(void);
 
+  int truncate();
+
   int delete_table(const char *from);
 
   int rename_table(const char * from, const char * to);