Gating tests: set TMPDIR=/var/tmp
    
    Gating tests are failing with ENOSPC. Try explicitly setting
    TMPDIR to /var/tmp which usually has more free space.
    
    Signed-off-by: Ed Santiago <santiago@redhat.com>
    (cherry picked from commit 6abb99385412cc5249e41a4907cb83a7ccb51508)
    Signed-off-by: Lokesh Mandvekar <lsm5@fedoraproject.org>