This following code contains a dead "if (dev).." block:
...
The reason is that the code starting with "if (dev).." is never called as
when we found an empty slot (dev == NULL) we break the loop and "if (dev).."
not works eiter the loop ends and we get out with "i >= slip_maxdev".
Signed-off-by: Matvejchikov Ilya <redacted>