ever since commit bc6a5d8e
    Date:   Wed Nov 15 16:52:44 2017 +0530
    Disable custom allocator
which makes FORCE_SYSALLOC redundant
which makes SYS_ALLOC redundant

Change-Id: I42e1d651473e7601e2280d9fb0662c89808c88f6
Reviewed-on: https://gerrit.libreoffice.org/58263
Tested-by: Jenkins
Reviewed-by: Michael Meeks <michael.meeks@collabora.com>