Repair wrong named definition aligned_u64

This repairs problem with compile library in userspace (libnl).
Signed-off-by: Jiří Župka <jzupka@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/if_packet.h

@@ -173,7 +173,7 @@ struct tpacket_hdr_v1 {
 	 *    you can see which blk[s] is[are] outstanding etc.
 	 * 3. Validate kernel code.
 	 */
-	aligned_u64	seq_num;
+	__aligned_u64	seq_num;
 
 	/*
 	 * ts_last_pkt: