[SCSI] zfcp: Replace local reference counting with common kref

Replace the local reference counting by already available mechanisms
offered by kref. Where possible existing device structures were used,
including the same functionality.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/s390/scsi/zfcp_dbf.c b/drivers/s390/scsi/zfcp_dbf.c
index 215b70749e95..fe818cd29dc1 100644
--- a/drivers/s390/scsi/zfcp_dbf.c
+++ b/drivers/s390/scsi/zfcp_dbf.c
@@ -1067,6 +1067,8 @@ err_out:
  */
 void zfcp_dbf_adapter_unregister(struct zfcp_dbf *dbf)
 {
+        if (!dbf)
+                return;
         debug_unregister(dbf->scsi);
         debug_unregister(dbf->san);
         debug_unregister(dbf->hba);