The smatch tool from http://repo.or.cz/w/smatch.git warns about this:
drivers/s390/scsi/zfcp_scsi.c +64 zfcp_scsi_command_fail(5) warn: variable dereferenced before check 'scpnt->device'
drivers/s390/scsi/zfcp_scsi.c +64 zfcp_scsi_command_fail(5) warn: variable dereferenced before check 'scpnt->device->host'
drivers/s390/scsi/zfcp_scsi.c +93 zfcp_scsi_queuecommand(23) warn: variable dereferenced before check 'unit'
Fix the first two warnings by removing the checks for scpnt->device
and -> host: As long as the SCSI command exists, there is also a
scsi_device and a Scsi_Host.
Fix the last warning by removing the BUG_ON checks in
zfcp_scsi_queuecommand, they are leftovers from previous paranoia
about wrong pointers between data structures.