The max-opencl-group-length ugly hack splits too long cell groups
into smaller ones, but 60a66bd5 accidentally made the temporary
group delete the array if the HW triggered this hack.
Testcase: 'SC_MAX_GROUP_LENGTH=1000 make CppunitTest_sc_copypaste'

Change-Id: I47ab08cd8511ad66e887c3c2d5eef25b08858c60
Reviewed-on: https://gerrit.libreoffice.org/69090Reviewed-by: Miklos Vajna <vmiklos@collabora.com>
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>