Fixed a few comments to make it compilable again

src/zinc/hal/systick.rs

@@ -20,6 +20,8 @@ This might be merged into generic timer interface. Systick is a bit specific in
 terms of interrupts, but PT should make the difference negligible.
 */
 
+/// A simple systick interface.
+#[experimental]
 pub trait Systick {
   /// Starts the systick timer.
   fn start(&self);

src/zinc/os/sched/mod.rs

@@ -13,7 +13,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-/// Tasks scheduling and management.
+//! Tasks scheduling and management.
 
 pub mod scheduler;
 pub mod stack;

src/zinc/os/sched/stack.rs

@@ -13,7 +13,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-/// Tasks stack management.
+//! Tasks stack management.
 
 /// StackManager provides scheduler with interface to manage task-specific stack
 /// pointer.

src/zinc/os/sched/task.rs

@@ -13,7 +13,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-/// Task structures.
+//! Task structures.
 
 use core::kinds::marker;
 
@@ -45,5 +45,6 @@ pub struct TasksIndex<'a> {
   /// Current running task index.
   pub current_task_index: u8,
 
+  /// Tasks are not copyable.
   pub no_copy: marker::NoCopy,
 }