vdsm: bridge: /proc/net/vlan may contain tabs

Reference-Url: http://lists.ovirt.org/pipermail/users/2013-February/012365.html
Reported-By: Jeff Bailey <bailey@cs.kent.edu>
Change-Id: I1aa5f1d1a88e41447ecd1eb2121d4b829f586b27
Signed-off-by: Alon Bar-Lev <alonbl@redhat.com>