Delete duplicate-value nodes from a sorted linked list Hacker rank solution in C

Node* RemoveDuplicates(Node *head)

{

    Node *c=head;

    if(head == NULL || head ->next == NULL)

        return head;

    while(c->next != NULL)

    {

        if(c->data == c->next->data)

        {

            c->next = c->next->next;

        }

        else

            c=c->next;           

    }

    return head;

}