KVM: VMX: eVMCS: make evmcs_sanitize_exec_ctrls() work again

It was noticed that evmcs_sanitize_exec_ctrls() is not being executed
nowadays despite the code checking 'enable_evmcs' static key looking
correct. Turns out, static key magic doesn't work in '__init' section
(and it is unclear when things changed) but setup_vmcs_config() is called
only once per CPU so we don't really need it to. Switch to checking
'enlightened_vmcs' instead, it is supposed to be in sync with
'enable_evmcs'.

Opportunistically make evmcs_sanitize_exec_ctrls '__init' and drop unneeded
extra newline from it.

Reported-by: Yang Weijiang <weijiang.yang@intel.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20201014143346.2430936-1-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>