KVM: Drop 'except' parameter from kvm_make_vcpus_request_mask()

Both remaining callers of kvm_make_vcpus_request_mask() pass 'NULL' for
'except' parameter so it can just be dropped.

No functional change intended ©.

Suggested-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210903075141.403071-6-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>