LCS recovery dumps when cable reconnect

LCS recovery dumps in irq routine when CCW address in
Subchannel Status Word (SCSW) is zero. This occurs
when recovery is driven after cable reconnect.

Signed-off-by: Klaus-D. Wacker <kdwacker@de.ibm.com>
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>