sendfile: remove .sendfile from filesystems that use generic_file_sendfile()

They can use generic_file_splice_read() instead. Since sys_sendfile() now
prefers that, there should be no change in behaviour.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/fs/adfs/file.c b/fs/adfs/file.c
index f544a28..36e381c 100644
--- a/fs/adfs/file.c
+++ b/fs/adfs/file.c
@@ -33,7 +33,7 @@
 	.fsync		= file_fsync,
 	.write		= do_sync_write,
 	.aio_write	= generic_file_aio_write,
-	.sendfile	= generic_file_sendfile,
+	.splice_read	= generic_file_splice_read,
 };
 
 const struct inode_operations adfs_file_inode_operations = {