scsi: Make checking the scsi_device_get() return value mandatory

Now that all scsi_device_get() callers check the return value of this
function, make checking that return value mandatory.

Signed-off-by: Bart Van Assche <[e-mail]>
Cc: Hannes Reinecke <[e-mail]>
Cc: Johannes Thumshirn <[e-mail]>
Reviewed-by: Johannes Thumshirn <[e-mail]>
Signed-off-by: Martin K. Petersen <[e-mail]>

include/scsi/scsi_device.h

···
 void scsi_attach_vpd(struct scsi_device *sdev);
 
 extern struct scsi_device *scsi_device_from_queue(struct request_queue *q);
-extern int scsi_device_get(struct scsi_device *);
+extern int __must_check scsi_device_get(struct scsi_device *);
 extern void scsi_device_put(struct scsi_device *);
 extern struct scsi_device *scsi_device_lookup(struct Scsi_Host *,
 					      uint, uint, u64);