target/arm/kvm64: Fix error returns

A couple return -EINVAL's forgot their '-'s.
Signed-off-by: NAndrew Jones <drjones@redhat.com>
Reviewed-by: NEric Auger <eric.auger@redhat.com>
Reviewed-by: NRichard Henderson <richard.henderson@linaro.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

target/arm/kvm64.c

@@ -854,7 +854,7 @@ int kvm_arch_put_registers(CPUState *cs, int level)
     write_cpustate_to_list(cpu, true);
 
     if (!write_list_to_kvmstate(cpu, level)) {
-        return EINVAL;
+        return -EINVAL;
     }
 
     kvm_arm_sync_mpstate_to_kvm(cpu);
@@ -995,7 +995,7 @@ int kvm_arch_get_registers(CPUState *cs)
     }
 
     if (!write_kvmstate_to_list(cpu)) {
-        return EINVAL;
+        return -EINVAL;
     }
     /* Note that it's OK to have registers which aren't in CPUState,
      * so we can ignore a failure return here.