lcs: Recognize return codes of ccw_device_set_online().

The creation of a new lcs device requires a call to the function
ccw_device_set_online() for the read and the write channel. Failure
of either call should terminate the lcs device creation immediately
with return code -ENODEV.

Signed-off-by: Klaus-Dieter Wacker <kdwacker@de.ibm.com>
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>