sky2: fix hard hang with netconsoling and iface going up

[ Upstream commit a11da890 ]

Printing anything over netconsole before hw is up and running is,
of course, not going to work.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>