hv_netvsc: make device_remove void

hv_netvsc: make device_remove void

BugLink: http://bugs.launchpad.net/bugs/1650059
Always returns 0 and no callers check.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit e08f3ea586d4145e36c77f0dd1602374b5d7e928)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Acked-by: Brad Figg <brad.figg@canonical.com>
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>