update code doc in linux-syscall
//!
//! ## Example
//! the syscall is called like this in the linux-loader:
-//! ```
-//! // let num = regs.rax as u32;
-//! // let args = [regs.rdi, regs.rsi, regs.rdx, regs.r10, regs.r8, regs.r9];
-//! // let mut syscall = Syscall {
-//! // thread,
-//! // #[cfg(feature = "std")]
-//! // syscall_entry: kernel_hal_unix::syscall_entry as usize,
-//! // #[cfg(not(feature = "std"))]
-//! // syscall_entry: 0,
-//! // spawn_fn: spawn,
-//! // regs,
-//! // exit: false,
-//! // };
-//! // let ret = syscall.syscall(num, args).await;
+//! ```ignore
+//! let num = regs.rax as u32;
+//! let args = [regs.rdi, regs.rsi, regs.rdx, regs.r10, regs.r8, regs.r9];
+//! let mut syscall = Syscall {
+//! thread,
+//! #[cfg(feature = "std")]
+//! syscall_entry: kernel_hal_unix::syscall_entry as usize,
+//! #[cfg(not(feature = "std"))]
+//! syscall_entry: 0,
+//! spawn_fn: spawn,
+//! regs,
+//! exit: false,
+//! };
+//! let ret = syscall.syscall(num, args).await;
//! ```
//!
