claw: use "claw" as root device name

Claw module cannot be loaded together with qeth, because "qeth" has
been errorneously used as root device name. It is changed into "claw".

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