diskfilter: fix double free of lv names for mdraid

diskfilter: fix double free of lv names for mdraid

Avoid micro-optimization in grub_diskfilter_make_raid and make sure
name and fullname are independent strings. This avoids need to special
case it everywhere else.

Also fix memory leak in failure case in grub_diskfilter_make_raid.

Closes: 41582
Last-Update: 2015-05-19
Bug-Ubuntu: https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/1330963
Origin: upstream, http://git.savannah.gnu.org/cgit/grub.git/commit/?id=fc535b32b9fe0cd84213724ffba43b98e2da6ab4
Patch-Name: fix_diskfilter_lv_name_dblfree.patch