
The uts created in do_ut_overlay() is not the one used in
cmd_ut_category(). Currently all tests are therefore called with
uts->priv = NULL and fail.
Using a static variable is the easiest fix here.
Fixes: e93232e15e
("test: overlay: Use cmd_ut_category()")
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>