KVM: selftests: x86: Fix test failure on arch lbr capable platforms

On Arch LBR capable platforms, LBR_FMT in perf capability msr is 0x3f,
so the last format test will fail. Use a true invalid format(0x30) for
the test if it's running on these platforms. Opportunistically change
the file name to reflect the tests actually carried out.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Yang Weijiang <weijiang.yang@intel.com>
Message-Id: <20220512084046.105479-1-weijiang.yang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>