LU-6137 ldiskfs: simplify nocmtime patch

LU-6137 ldiskfs: simplify nocmtime patch

Simplify the nocmtime patch by patching only ext4_current_time(),
this fixed the defect that original patch doesn't handle setacl
code path, it can also avoid the risk of future changes adding
new places that needs to be fixed.

Remove the obsolete xattr-no-update-ctime patch.

Signed-off-by: Anreas Dilger <andreas.dilger@intel.com>
Signed-off-by: Niu Yawei <yawei.niu@intel.com>
Change-Id: I02928c4f867e9476f0bc1815dd3256e3d79dadf7
Reviewed-on: http://review.whamcloud.com/13705
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Bobi Jam <bobijam@hotmail.com>
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Reviewed-by: Fan Yong <fan.yong@intel.com>