KVM: s390: selftests: fix ucontrol memory region test

With the latest patch, attempting to create a memslot from userspace
will result in an EEXIST error for UCONTROL VMs, instead of EINVAL,
since the new memslot will collide with the internal memslot. There is
no simple way to bring back the previous behaviour.

This is not a problem, but the test needs to be fixed accordingly.

Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com>
Link: https://lore.kernel.org/r/20250123144627.312456-5-imbrenda@linux.ibm.com


Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Message-ID: <20250123144627.312456-5-imbrenda@linux.ibm.com>