LU-2038 osd: Rename do_*punch to dbo_*punch

LU-2038 osd: Rename do_*punch to dbo_*punch

Minor fix where dt_body_operations::do_punch and
dt_body_operations::do_declare_punch were renamed to
dt_body_operations::dbo_punch and
dt_body_operations::dbo_declare_punch, respectively, to keep the
field names consistent.

Signed-off-by: Girish Shilamkar <gshilamkar@ddn.com>
Change-Id: Id807805bd69bb20460898552830a658d8a25c238
Reviewed-on: http://review.whamcloud.com/5895
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Li Wei <wei.g.li@intel.com>
Reviewed-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>