net: tsi108: use NULL for pointer-typed argument

The first argument of pci_free_consistent has type struct pci_dev *, so use
NULL instead of 0.

The semantic patch that performs this transformation is as follows:
(http://coccinelle.lip6.fr/

)

// <smpl>
@@
@@
pci_free_consistent(
- 0
+ NULL
  , ...)
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>