libceph: drop return value from page vector copy routines

The return values provided for ceph_copy_to_page_vector() and
ceph_copy_from_page_vector() serve no purpose, so get rid of them.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
diff --git a/include/linux/ceph/libceph.h b/include/linux/ceph/libceph.h
index 2250f8b..29818fc 100644
--- a/include/linux/ceph/libceph.h
+++ b/include/linux/ceph/libceph.h
@@ -232,10 +232,10 @@
 extern int ceph_copy_user_to_page_vector(struct page **pages,
 					 const void __user *data,
 					 loff_t off, size_t len);
-extern int ceph_copy_to_page_vector(struct page **pages,
+extern void ceph_copy_to_page_vector(struct page **pages,
 				    const void *data,
 				    loff_t off, size_t len);
-extern int ceph_copy_from_page_vector(struct page **pages,
+extern void ceph_copy_from_page_vector(struct page **pages,
 				    void *data,
 				    loff_t off, size_t len);
 extern int ceph_copy_page_vector_to_user(struct page **pages, void __user *data,