Write a C function, remove_item(), that takes an integer argument, num, and a linked list, list, (possibly NULL) of these structures. remove_item() removes the first node of the list with the given value, if any, and returns a pointer to the head of the modified list. If a node is removed, it should be free()d. Write robust code. \[ \text { node } * \text { remove_item(int num, node } * \text { list) }\{ \]