Kernel+LibC: Add some errno codes

Kernel now returns ENOMEM and other errnos, so we dont have to write
error messages

BAN/include/BAN/LinkedList.h

@@ -288,7 +288,7 @@ namespace BAN
 	{
 		Node* node = (Node*)BAN::allocator(sizeof(Node));
 		if (node == nullptr)
-			return Error::from_string("LinkedList: Could not allocate memory");	
+			return Error::from_errno(ENOMEM);	
 		return node;
 	}