runtime: fix some comments

This commint include two types of fixes for comments
in src/runtime/containerd-shim-v2/start.go.

- Update comment for calling of watchOOMEvents.
- Comments without heading spaces.

Fixes: #1750

Signed-off-by: bin <bin@hyper.sh>

src/runtime/containerd-shim-v2/start.go

@@ -37,8 +37,8 @@ func startContainer(ctx context.Context, s *service, c *container) error {
 		}
 		go watchSandbox(ctx, s)
 
-		// We don't rely on the context passed to startContainer as it can be cancelled after
-		// this rpc call.
+		// We use s.ctx(`ctx` derived from `s.ctx`) to check for cancellation of the
+		// shim context and the context passed to startContainer for tracing.
 		go watchOOMEvents(ctx, s)
 	} else {
 		_, err := s.sandbox.StartContainer(ctx, c.id)