xen-netback: fix sparse warning

Fix warning about 0 used as NULL.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
stephen hemminger 2013-04-10 10:54:46 +00:00 • committed by David S. Miller
commit 9eaee8beee