block,ide: simplify bdops->set_capacity() to ->unlock_native_capacity()

bdops->set_capacity() is unnecessarily generic.  All that's required
is a simple one way notification to lower level driver telling it to
try to unlock native capacity.  There's no reason to pass in target
capacity or return the new capacity.  The former is always the
inherent native capacity and the latter can be handled via the usual
device resize / revalidation path.  In fact, the current API is always
used that way.

Replace ->set_capacity() with ->unlock_native_capacity() which take
only @disk and doesn't return anything.  IDE which is the only current
user of the API is converted accordingly.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/drivers/ide/ide-gd.c b/drivers/ide/ide-gd.c
index c32d83996..c102d23 100644
--- a/drivers/ide/ide-gd.c
+++ b/drivers/ide/ide-gd.c
@@ -288,17 +288,14 @@
 	return ret;
 }
 
-static unsigned long long ide_gd_set_capacity(struct gendisk *disk,
-					      unsigned long long capacity)
+static void ide_gd_unlock_native_capacity(struct gendisk *disk)
 {
 	struct ide_disk_obj *idkp = ide_drv_g(disk, ide_disk_obj);
 	ide_drive_t *drive = idkp->drive;
 	const struct ide_disk_ops *disk_ops = drive->disk_ops;
 
-	if (disk_ops->set_capacity)
-		return disk_ops->set_capacity(drive, capacity);
-
-	return drive->capacity64;
+	if (disk_ops->unlock_native_capacity)
+		disk_ops->unlock_native_capacity(drive);
 }
 
 static int ide_gd_revalidate_disk(struct gendisk *disk)
@@ -329,7 +326,7 @@
 	.locked_ioctl		= ide_gd_ioctl,
 	.getgeo			= ide_gd_getgeo,
 	.media_changed		= ide_gd_media_changed,
-	.set_capacity		= ide_gd_set_capacity,
+	.unlock_native_capacity	= ide_gd_unlock_native_capacity,
 	.revalidate_disk	= ide_gd_revalidate_disk
 };