dec_connection_count() definition doesn't match its declaration

dec_connection_count() is declared in include/thread_pool_priv.h as follows:

/* Decrement connection counter */
void dec_connection_count();

However, the threadpool patch has added the 'thd' argument to the definition without changing the declaration:

void dec_connection_count(THD *thd)
{
  mysql_mutex_lock(&LOCK_connection_count);
  (*thd->scheduler->connection_count)--;
  mysql_mutex_unlock(&LOCK_connection_count);
}