net-sysfs: trigger netlink notification on ifalias change via sysfs

This patch adds netlink notifications on iflias changes via sysfs.
makes it consistent with the netlink path which also calls
netdev_state_change. Also makes it consistent with other sysfs
netdev_store operations.

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>