tun: Turn tun_flow_init() into void fn
tun: Turn tun_flow_init() into void fn

This routine doesn't fail since 9fdc6bef (tuntap: dont use a private kmem_cache)
so it makes sense to compact the code a little bit.

Signed-off-by: Pavel Emelyanov <c9a32589e048e044184536f7ac71ef92fe82df3e@parallels.com>
Signed-off-by: David S. Miller <fe08d3c717adf2ae63592e4c9aec6e3e404d8e3e@davemloft.net>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs