nVMX: Drop less-than-useless ept_sync() wrapper

Drop ept_sync(), it's nothing more than a wrapper to invept() with
open-coded "assertions" that the desired flavor of INVEPT is supported.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211125012857.508243-26-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>