KVM: PPC: Book3S HV: Fix the set_one_reg for MMCR3

The kvmppc_set_one_reg_hv() wrongly get() the value
instead of set() for MMCR3. Fix the same.

Fixes: 5752fe0 ("KVM: PPC: Book3S HV: Save/restore new PMU registers")
Signed-off-by: Shivaprasad G Bhat <sbhat@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/171759276847.1480.16387950124201117847.stgit@linux.ibm.com

arch/powerpc/kvm/book3s_hv.c

@@ -2540,7 +2540,7 @@ static int kvmppc_set_one_reg_hv(struct kvm_vcpu *vcpu, u64 id,
 		vcpu->arch.mmcrs = set_reg_val(id, *val);
 		break;
 	case KVM_REG_PPC_MMCR3:
-		*val = get_reg_val(id, vcpu->arch.mmcr[3]);
+		kvmppc_set_mmcr_hv(vcpu, 3, set_reg_val(id, *val));
 		break;
 	case KVM_REG_PPC_PMC1 ... KVM_REG_PPC_PMC8:
 		i = id - KVM_REG_PPC_PMC1;