Smack: ignore private inode for smack_file_receive

The dmabuf fd can be shared between processes via unix domain
socket. The file of dmabuf fd is came from anon_inode. The inode
has no set and get xattr operations, so it can not be shared
between processes with smack. This patch fixes just to ignore
private inode including anon_inode for smack_file_receive.

Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>