Fix some import conventions

src/bin/fish.rs

@@ -64,6 +64,7 @@
     wchar::prelude::*,
     wutil::waccess,
 };
+use libc::STDIN_FILENO;
 #[cfg(feature = "embed-data")]
 use rust_embed::RustEmbed;
 use std::ffi::{CString, OsStr, OsString};
@@ -371,7 +372,7 @@ fn fish_parse_opt(args: &mut [WString], opts: &mut FishCmdOpts) -> ControlFlow<i
     // We are an interactive session if we have not been given an explicit
     // command or file to execute and stdin is a tty. Note that the -i or
     // --interactive options also force interactive mode.
-    if opts.batch_cmds.is_empty() && optind == args.len() && isatty(libc::STDIN_FILENO) {
+    if opts.batch_cmds.is_empty() && optind == args.len() && isatty(STDIN_FILENO) {
         set_interactive_session(true);
     }
 

src/builtins/fish_indent.rs

@@ -886,7 +886,7 @@ fn throwing_main() -> i32 {
     use crate::io::FdOutputStream;
     use crate::io::IoChain;
     use crate::io::OutputStream::Fd;
-    use libc::{STDERR_FILENO, STDOUT_FILENO};
+    use libc::{STDERR_FILENO, STDIN_FILENO, STDOUT_FILENO};
 
     topic_monitor_init();
     threads::init();
@@ -895,7 +895,7 @@ fn throwing_main() -> i32 {
     let mut err = Fd(FdOutputStream::new(STDERR_FILENO));
     let io_chain = IoChain::new();
     let mut streams = IoStreams::new(&mut out, &mut err, &io_chain);
-    streams.stdin_fd = libc::STDIN_FILENO;
+    streams.stdin_fd = STDIN_FILENO;
     // Using the user's default locale could be a problem if it doesn't use UTF-8 encoding. That's
     // because the fish project assumes Unicode UTF-8 encoding in all of its scripts.
     //

src/builtins/fish_key_reader.rs

@@ -298,7 +298,7 @@ fn throwing_main() -> i32 {
         return s.builtin_status_code();
     }
 
-    if !isatty(libc::STDIN_FILENO) {
+    if !isatty(STDIN_FILENO) {
         streams
             .err
             .appendln(wgettext!("Stdin must be attached to a tty."));