LU-3373 misc: small changes for 3.10 server support

LU-3373 misc: small changes for 3.10 server support

--quota use struct kqid as parameter
--export ext4_dec/inc_count for nlink count
--ext4_find_entry & ext4_journal_start_sb changes
--iop->truncate removed
--other trival changes to calm compiler warning

Signed-off-by: yang sheng <yang.sheng@intel.com>
Change-Id: I77aedb624033debe37cb6928721c2550498ad72d
Reviewed-on: http://review.whamcloud.com/7794
Tested-by: Jenkins
Reviewed-by: James Simmons <uja.ornl@gmail.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>