Actually the assembler requires lowercase /safeseh, oddly enough.

Change-Id: I1569409a2d6358282a7463ea996a6b1615e6ed8c
(cherry picked from commit 8f3ca083)
Reviewed-on: https://gerrit.libreoffice.org/47584Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>