Description of problem:
Demotion failure for char type file. It should fail all special(CHAR, BLOCK, SOCKET etc) type files other than regular, but for me issue is seen in char type file. From the logs, it is clear that lookup(dht_revalidate_cbk) on this file failed in cold tier due to type mismatch 

Version-Release number of selected component (if applicable):
mainline

How reproducible:
always

Steps to Reproduce:
1.Create and start a tier volume
2.set tier mod= test(preferable to use other demotion paremeters)
3.mount the volume(any protocol) 
4.create a char type file using mknod
5.after some time(promotion will happen)
6.When tier daemon tries to demote, it will fail. Failure messages are flooded in tier log

Actual results:
Demotion failed

Expected results:
Demotion should not fail

Additional info:
snippet from tier daemon log :

[2015-12-11 13:00:10.407115] E [MSGID: 109037] [tier.c:1489:tier_start] 0-test-tier-dht: Demotion failed
13:00:10.355941] and [2015-12-11 13:00:20.417126]
[2015-12-11 13:00:20.421914] W [MSGID: 109008] [dht-common.c:826:dht_revalidate_cbk] 0-test-cold-dht: mismatching filetypes 01 v/s 05 for //char, gfid = b7f40bcd-3153-4619-bd19-28797d1b5ce5
[2015-12-11 13:00:20.421987] W [MSGID: 109023] [dht-rebalance.c:969:migrate_special_files] 0-test-tier-dht: //char: lookup failed (Invalid argument)
[2015-12-11 13:00:20.422605] E [MSGID: 109037] [tier.c:489:tier_migrate_using_query_file] 0-test-tier-dht: Failed to migrate char


char is file name