Ocfs2: Teach local-mounted ocfs2 to handle unwritten_extents correctly.

Oops, local-mounted of 'ocfs2_fops_no_plocks' is just missing the support
of unwritten_extents/punching-hole due to no func pointer was given correctly
to '.follocate' field.
Signed-off-by: Tristan Ye <tristan.ye@oracle.com>

fs/ocfs2/file.c

@@ -2670,6 +2670,7 @@ const struct file_operations ocfs2_fops_no_plocks = {
 	.flock		= ocfs2_flock,
 	.splice_read	= ocfs2_file_splice_read,
 	.splice_write	= ocfs2_file_splice_write,
+	.fallocate	= ocfs2_fallocate,
 };
 
 const struct file_operations ocfs2_dops_no_plocks = {