ps3disk: passing wrong variable to bvec_kunmap_irq()

This should pass "buf" to bvec_kunmap_irq() instead of "bv".  The api is
like kmap_atomic() instead of kmap().

Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Geoff Levand <geoff@infradead.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
diff --git a/drivers/block/ps3disk.c b/drivers/block/ps3disk.c
index e9da874..03688c2 100644
--- a/drivers/block/ps3disk.c
+++ b/drivers/block/ps3disk.c
@@ -113,7 +113,7 @@
 			memcpy(buf, dev->bounce_buf+offset, size);
 		offset += size;
 		flush_kernel_dcache_page(bvec->bv_page);
-		bvec_kunmap_irq(bvec, &flags);
+		bvec_kunmap_irq(buf, &flags);
 		i++;
 	}
 }