s390/dasd: move dasd_eckd_read_fc_security

dasd_eckd_read_conf is called multiple times during device setup but the
fc_security feature needs to be read only once. So move it into the calling
function.

Signed-off-by: Stefan Haberland <sth@linux.ibm.com>
Reviewed-by: Jan Hoeppner <hoeppner@linux.ibm.com>
Link: https://lore.kernel.org/r/20211020115124.1735254-5-sth@linux.ibm.com


Signed-off-by: Jens Axboe <axboe@kernel.dk>