build: fix clippy ptr arg issue

CI reports errors:

error: writing `&Vec` instead of `&[_]` involves a new object where a slice will do
    --> arch/src/x86_64/mod.rs:1351:19
     |
1351 |     epc_sections: &Vec<SgxEpcSection>,
     |                   ^^^^^^^^^^^^^^^^^^^ help: change this to: `&[SgxEpcSection]`
     |
     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#ptr_arg
     = note: `-D clippy::ptr-arg` implied by `-D warnings`
     = help: to override `-D warnings` add `#[allow(clippy::ptr_arg)]`

Signed-off-by: Yi Wang <foxywang@tencent.com>

arch/src/x86_64/mod.rs

@@ -1368,7 +1368,7 @@ fn update_cpuid_topology(
 // sections exposed to the guest.
 fn update_cpuid_sgx(
     cpuid: &mut Vec<CpuIdEntry>,
-    epc_sections: &Vec<SgxEpcSection>,
+    epc_sections: &[SgxEpcSection],
 ) -> Result<(), Error> {
     // Something's wrong if there's no EPC section.
     if epc_sections.is_empty() {