Adding inequality conditions (trekhleb#489)

A quick fix to add inequality conditions wherever needed.

Co-authored-by: Oleksii Trekhleb <[email protected]>

Author: surajhell88

src/data-structures/doubly-linked-list/README.md

@@ -66,14 +66,14 @@ Remove(head, value)
     return true
   end if
   n ← head.next
-  while n = ø and value !== n.value
+  while n != ø and value !== n.value
     n ← n.next
   end while
   if n = tail
     tail ← tail.previous
     tail.next ← ø
     return true
-  else if n = ø
+  else if n != ø
     n.previous.next ← n.next
     n.next.previous ← n.previous
     return true
@@ -89,7 +89,7 @@ ReverseTraversal(tail)
   Pre: tail is the node of the list to traverse
   Post: the list has been traversed in reverse order
   n ← tail
-  while n = ø
+  while n != ø
     yield n.value
     n ← n.previous
   end while