[SCSI] zfcp: fix bug during adapter shutdown

Fixes a race between zfcp_fsf_req_dismiss_all and
zfcp_qdio_reqid_check. During adapter shutdown it occurred that a
request was cleaned up twice. First during its normal
completion. Second when dismiss_all was called.  The fix is to
serialize access to fsf request list between zfcp_fsf_req_dismiss_all
and zfcp_qdio_reqid_check and delete a fsf request from the list if
its completion is triggered.  (Additionally a rwlock was replaced by a
spinlock and fsf_req_cleanup was eliminated.)

Signed-off-by: Andreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
diff --git a/drivers/s390/scsi/zfcp_ext.h b/drivers/s390/scsi/zfcp_ext.h
index d5fd433..8f0da2e 100644
--- a/drivers/s390/scsi/zfcp_ext.h
+++ b/drivers/s390/scsi/zfcp_ext.h
@@ -116,7 +116,7 @@
 					   struct timer_list*, int);
 extern int  zfcp_fsf_req_complete(struct zfcp_fsf_req *);
 extern void zfcp_fsf_incoming_els(struct zfcp_fsf_req *);
-extern void zfcp_fsf_req_cleanup(struct zfcp_fsf_req *);
+extern void zfcp_fsf_req_free(struct zfcp_fsf_req *);
 extern struct zfcp_fsf_req *zfcp_fsf_send_fcp_command_task_management(
 	struct zfcp_adapter *, struct zfcp_unit *, u8, int);
 extern struct zfcp_fsf_req *zfcp_fsf_abort_fcp_command(