scsi: sd: Introduce a new local variable in sd_check_events()

Instead of using 'retval' to represent first a SCSI status and later
whether or not a disk change event occurred, introduce a new variable for
the latter purpose.

Link: https://lore.kernel.org/r/20210415220826.29438-17-bvanassche@acm.org
Cc: Christoph Hellwig <hch@lst.de>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/sd.c

@@ -1623,6 +1623,7 @@ static unsigned int sd_check_events(struct gendisk *disk, unsigned int clearing)
 	struct scsi_disk *sdkp = scsi_disk_get(disk);
 	struct scsi_device *sdp;
 	int retval;
+	bool disk_changed;
 
 	if (!sdkp)
 		return 0;
@@ -1680,10 +1681,10 @@ static unsigned int sd_check_events(struct gendisk *disk, unsigned int clearing)
 	 *	Medium present state has changed in either direction.
 	 *	Device has indicated UNIT_ATTENTION.
 	 */
-	retval = sdp->changed ? DISK_EVENT_MEDIA_CHANGE : 0;
+	disk_changed = sdp->changed;
 	sdp->changed = 0;
 	scsi_disk_put(sdkp);
-	return retval;
+	return disk_changed ? DISK_EVENT_MEDIA_CHANGE : 0;
 }
 
 static int sd_sync_cache(struct scsi_disk *sdkp, struct scsi_sense_hdr *sshdr)