pata_scc: kill useless check in scc_postreset()

The device control register exists and its address is set by scc_setup_ports(),
hence the check is useless...

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>