[SCSI] zfcp: returning an ERR_PTR where a NULL value is expected

Aborting a SCSI cmnd might requrie to send a abort_fsf_cmnd. If the
creation of this fsf_req fails an ERR_PTR is returned where a NULL
value would be expected as an error indicator. This ERR_PTR is
dereferenced as valid fsf_req in succeeding processing leading to
an error.
Signed-off-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

drivers/s390/scsi/zfcp_fsf.c

@@ -930,8 +930,10 @@ struct zfcp_fsf_req *zfcp_fsf_abort_fcp_command(unsigned long old_req_id,
 		goto out;
 	req = zfcp_fsf_req_create(adapter, FSF_QTCB_ABORT_FCP_CMND,
 				  req_flags, adapter->pool.fsf_req_abort);
-	if (IS_ERR(req))
+	if (IS_ERR(req)) {
+		req = NULL;
 		goto out;
+	}
 
 	if (unlikely(!(atomic_read(&unit->status) &
 		       ZFCP_STATUS_COMMON_UNBLOCKED)))
@@ -2443,8 +2445,10 @@ struct zfcp_fsf_req *zfcp_fsf_send_fcp_ctm(struct zfcp_adapter *adapter,
 		goto out;
 	req = zfcp_fsf_req_create(adapter, FSF_QTCB_FCP_CMND, req_flags,
 				  adapter->pool.fsf_req_scsi);
-	if (IS_ERR(req))
+	if (IS_ERR(req)) {
+		req = NULL;
 		goto out;
+	}
 
 	req->status |= ZFCP_STATUS_FSFREQ_TASK_MANAGEMENT;
 	req->data = unit;