KVM: selftests: Move raw KVM_SET_USER_MEMORY_REGION helper to utils

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2074832



commit 3d7d6043
Author: Sean Christopherson <seanjc@google.com>
Date:   Sat Feb 26 00:15:43 2022 +0000

    KVM: selftests: Move raw KVM_SET_USER_MEMORY_REGION helper to utils

    Move set_memory_region_test's KVM_SET_USER_MEMORY_REGION helper to KVM's
    utils so that it can be used by other tests.  Provide a raw version as
    well as an assert-success version to reduce the amount of boilerplate
    code need for basic usage.

    No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
    Message-Id: <20220226001546.360188-26-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>