KVM: VMX: fix sparse warning

Impact: make global function static

  arch/x86/kvm/vmx.c:134:3: warning: symbol 'vmx_capability' was not declared. Should it be static?
Signed-off-by: NHannes Eder <hannes@hanneseder.net>
Signed-off-by: NAvi Kivity <avi@redhat.com>

arch/x86/kvm/vmx.c

@@ -128,7 +128,7 @@ static struct vmcs_config {
 	u32 vmentry_ctrl;
 } vmcs_config;
 
-struct vmx_capability {
+static struct vmx_capability {
 	u32 ept;
 	u32 vpid;
 } vmx_capability;