scsi: esp_scsi: use strong typing for the dev field

esp->dev is a void pointer that points either to a struct device, or a
struct platform_device.  As we can easily get from the device to the
platform_device if needed change it to always point to a struct device
and properly type the pointer to avoid errors.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
diff --git a/drivers/scsi/esp_scsi.h b/drivers/scsi/esp_scsi.h
index 8163dca..f98abd0 100644
--- a/drivers/scsi/esp_scsi.h
+++ b/drivers/scsi/esp_scsi.h
@@ -435,7 +435,7 @@ struct esp {
 	const struct esp_driver_ops *ops;
 
 	struct Scsi_Host	*host;
-	void			*dev;
+	struct device		*dev;
 
 	struct esp_cmd_entry	*active_cmd;