target-ppc: Fix kvmppc_set_compat to use negotiated cpu-version

By mistake, QEMU uses the maximum compatibility level from the command
line instead of the value negotiated in client-architecture-support call.

This replaces @max_compat with @cpu_version. This only affects guests
which do not support the host CPU.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Alexander Graf <agraf@suse.de>

target-ppc/translate_init.c

@@ -9137,7 +9137,7 @@ int ppc_set_compat(PowerPCCPU *cpu, uint32_t cpu_version)
         break;
     }
 
-    if (kvm_enabled() && kvmppc_set_compat(cpu, cpu->max_compat) < 0) {
+    if (kvm_enabled() && kvmppc_set_compat(cpu, cpu->cpu_version) < 0) {
         error_report("Unable to set compatibility mode in KVM");
         ret = -1;
     }