hyperv: Fix race between probe and open calls

Moving the register_netdev to the end of probe to prevent
possible open call happens before NetVSP is connected.

Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --cc drivers/net/hyperv/netvsc_drv.c
Simple merge