KVM: x86/emulate: Remove unused "tss_selector" of task_switch_{16, 32}()

The "u16 tss_selector" parameter of task_switch_{16, 32}()
is not used, so remove it. No functional change intended.

Signed-off-by: Jinrong Liang <cloudliang@tencent.com>
Message-Id: <20220125095909.38122-16-cloudliang@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>