vrrp: Fix initial interface status flag value for VMAC interface

In commit a05a503, "vrrp: Fix sync of interface status flag when using VMAC
interface", no inital value for the VMAC interface status flag was set. Due
to that the VMAC interface flags shall follow the base interface, the base
interface status flags value shall be copied to the VMAC interface status
flags after the VMAC interface has been created.

Signed-off-by: Jonas Johansson <jonasj76@gmail.com>
Merge pull request #79 from jonasj76/vmac-reflect-2

Fix initial interface status flag value for VMAC interface