missing forward declarations in scsi_eh.h

@@ -1,6 +1,10 @@
 #ifndef _SCSI_SCSI_EH_H
 #define _SCSI_SCSI_EH_H
 
+struct scsi_cmnd;
+struct scsi_device;
+struct Scsi_Host;
+
 extern void scsi_add_timer(struct scsi_cmnd *, int,
 			   void (*)(struct scsi_cmnd *));
 extern int scsi_delete_timer(struct scsi_cmnd *);