KVM: s390: selftests: Add has device attr check to uc_attr_mem_limit selftest

KVM: s390: selftests: Add has device attr check to uc_attr_mem_limit selftest

Fixup the uc_attr_mem_limit test case to also cover the
KVM_HAS_DEVICE_ATTR ioctl.

Signed-off-by: Christoph Schlameuss <schlameuss@linux.ibm.com>
Tested-by: Hariharan Mari <hari55@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Link: https://lore.kernel.org/r/20241216092140.329196-7-schlameuss@linux.ibm.com
Message-ID: <20241216092140.329196-7-schlameuss@linux.ibm.com>
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>