block_device_operations->release() should return void

The value passed is 0 in all but "it can never happen" cases (and those
only in a couple of drivers) *and* it would've been lost on the way
out anyway, even if something tried to pass something meaningful.
Just don't bother.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/drivers/s390/block/scm_blk.c b/drivers/s390/block/scm_blk.c
index b303cab..5d73e6e 100644
--- a/drivers/s390/block/scm_blk.c
+++ b/drivers/s390/block/scm_blk.c
@@ -123,10 +123,9 @@
 	return scm_get_ref();
 }
 
-static int scm_release(struct gendisk *gendisk, fmode_t mode)
+static void scm_release(struct gendisk *gendisk, fmode_t mode)
 {
 	scm_put_ref();
-	return 0;
 }
 
 static const struct block_device_operations scm_blk_devops = {