LU-709 build: clean up i_mutex/i_private/quota_info macros

LU-709 build: clean up i_mutex/i_private/quota_info macros

1. struct inode has i_mutex instead of i_sem since v2.6.16
2. struct inode has i_private since v2.6.17
3. struct quota_info uses mutex instead semaphore since v2.6.17
4. move LC_SECURITY_PLUG to under v2.6.27

Signed-off-by: Peng Tao <tao.peng@emc.com>
Change-Id: I587d18a8d63927aa0a668268d252f71e7f224b50
Reviewed-on: http://review.whamcloud.com/2318
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Yang Sheng <ys@whamcloud.com>
Reviewed-by: Niu Yawei <niu@whamcloud.com>