doc: Fix code snippet tag

cargo doc tag which marks a snippet not to be ran should be `no_run`
instead of `norun`.

Signed-off-by: Ruoqing He <[email protected]>

Author: RuoqingHe

kvm-bindings/src/x86_64/fam_wrappers.rs

@@ -135,7 +135,7 @@ pub struct kvm_xsave2 {
     /// Note that `KVM_CHECK_EXTENSION(KVM_CAP_XSAVE2)` returns the size of the entire
     /// `kvm_xsave` structure, e.g. the sum of header and FAM. Thus, this `len` field
     /// is equal to
-    /// ```norun
+    /// ```no_run
     /// (KVM_CHECK_EXTENSION(KVM_CAP_XSAVE2) - sizeof::<kvm_xsave>()).div_ceil(sizeof::<__u32>())
     /// ```
     pub len: usize,