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/ramfs/file-nommu.c b/fs/ramfs/file-nommu.c
index 5d258c4..cad2b7a 100644
--- a/fs/ramfs/file-nommu.c
+++ b/fs/ramfs/file-nommu.c
@@ -42,7 +42,7 @@
 	.write			= do_sync_write,
 	.aio_write		= generic_file_aio_write,
 	.fsync			= simple_sync_file,
-	.sendfile		= generic_file_sendfile,
+	.splice_read		= generic_file_splice_read,
 	.llseek			= generic_file_llseek,
 };