Function sys_dlist_peek_prev_no_check

pub unsafe extern "C" fn sys_dlist_peek_prev_no_check(
    list: *mut _dnode,
    node: *mut _dnode,
) -> *mut _dnode

@brief get a reference to the previous item in the list, node is not NULL

Faster than sys_dlist_peek_prev() if node is known not to be NULL.

@param list the doubly-linked list to operate on @param node the node from which to get the previous element in the list

@return a pointer to the previous element from a node, NULL if node is the tail