rem: void remove_cell_from_htable(struct h_table *table, struct h_link *link)
add: int remove_cell_from_htable(struct h_table *table, struct h_link *link)
context: void remove_cell_from_htable(struct h_table *table, struct h_link *link){	lock_get( table->mutex );	list_del( &(link->lh) );	lock_release( table->mutex );}