As we are currently unable to fix the problem with carrier and protocol
state signaling in net core I've to disable netif_carrier_off()
calls used by WAN protocol drivers. The attached patch should make
them working again.

The remaining netif_carrier_*() calls in hdlc_fr.c are fine as they
don't touch the physical device.
Signed-off-by: NKrzysztof Halasa <khc@pm.waw.pl>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>