[S390] sparse: fix sparse NULL pointer warnings

Fix two NULL pointer warnings in the dasd driver:

drivers/s390/block/dasd_eckd.c:2353:20: warning: Using plain integer as NULL pointer
drivers/s390/block/dasd_eckd.c:2415:44: warning: Using plain integer as NULL pointer

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
1 file changed