Cleanup obj_dat.h, obj_dat.pl

The recent merge of https://github.com/openssl/openssl/pull/1264


removed some trailing whitespace from the generated file obj_dat.h.
Unfortunately obj_dat.pl kept re-adding it.  Clean up the
script and the output it generates.

Add 'use strict / use warnings'

Reviewed-by: Richard Levitte <levitte@openssl.org>