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/sysv/file.c b/fs/sysv/file.c
index 0732ddb..589be21 100644
--- a/fs/sysv/file.c
+++ b/fs/sysv/file.c
@@ -27,7 +27,7 @@
 	.aio_write	= generic_file_aio_write,
 	.mmap		= generic_file_mmap,
 	.fsync		= sysv_sync_file,
-	.sendfile	= generic_file_sendfile,
+	.splice_read	= generic_file_splice_read,
 };
 
 const struct inode_operations sysv_file_inode_operations = {