Fix clippy lints

Author: MikailBag

src/linux.rs

@@ -123,13 +123,13 @@ fn handle_input_io(spec: InputSpecification) -> Result<(Option<Fd>, Fd), Error>
             let file = file.into_raw_fd();
             Ok((None, file))
         }
-        InputSpecificationData::Null => Ok((None, -1 as Fd)),
+        InputSpecificationData::Null => Ok((None, -1)),
     }
 }
 
 fn handle_output_io(spec: OutputSpecification) -> Result<(Option<Fd>, Fd), Error> {
     match spec.0 {
-        OutputSpecificationData::Null => Ok((None, -1 as Fd)),
+        OutputSpecificationData::Null => Ok((None, -1)),
         OutputSpecificationData::Handle(rh) => Ok((None, rh as Fd)),
         OutputSpecificationData::Pipe => {
             let mut h_read = 0;

src/linux/pipe.rs

@@ -74,7 +74,7 @@ impl io::Write for LinuxWritePipe {
 
 pub(crate) fn setup_pipe(read_end: &mut Fd, write_end: &mut Fd) -> Result<(), crate::linux::Error> {
     unsafe {
-        let mut ends = [0 as Fd; 2];
+        let mut ends = [0; 2];
         let ret = libc::pipe2(ends.as_mut_ptr(), libc::O_CLOEXEC);
         if ret == -1 {
             err_exit("pipe");

src/linux/zygote.rs

@@ -170,7 +170,7 @@ fn do_exec(mut arg: DoExecArg) -> ! {
             if -1 == libc::fcntl(fd, libc::F_SETFD, libc::FD_CLOEXEC) {
                 let fd_info_path = format!("/proc/self/fd/{}", fd);
                 let fd_info_path = CString::new(fd_info_path.as_str()).unwrap();
-                let mut fd_info = [0 as c_char; 4096];
+                let mut fd_info = [0; 4096];
                 libc::readlink(fd_info_path.as_ptr(), fd_info.as_mut_ptr(), 4096);
                 let fd_info = CString::from_raw(fd_info.as_mut_ptr());
                 let fd_info = fd_info.to_str().unwrap();
@@ -420,7 +420,7 @@ fn start_zygote_caller(
     let mut logger = crate::linux::util::strace_logger();
     write!(logger, "sandbox {}: thread A (main)", &jail_options.jail_id).unwrap();
 
-    let mut zygote_pid_bytes = [0 as u8; 4];
+    let mut zygote_pid_bytes = [0; 4];
 
     // Wait until zygote is ready.
     // Zygote is ready when zygote launcher returns it's pid