i386: kvm: kvm_arch_get_supported_cpuid: clean up has_kvm_features check

Instead of a function-specific has_kvm_features variable, simply use a
"found" variable that will be checked in case we have to use the legacy
get_para_features() interface.

No behavior change, just code cleanup.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
