Clean up some std::io calls

fish-rust/src/path.rs

@@ -14,7 +14,7 @@ use errno::{errno, set_errno, Errno};
 use libc::{EACCES, ENOENT, ENOTDIR, F_OK, X_OK};
 use once_cell::sync::Lazy;
 use std::ffi::OsStr;
-use std::io::{ErrorKind, Write};
+use std::io::ErrorKind;
 use std::os::unix::prelude::*;
 
 /// Returns the user configuration directory for fish. If the directory or one of its parents
@@ -169,7 +169,7 @@ fn maybe_issue_path_warning(
             )
         );
     }
-    let _ = std::io::stdout().write(&[b'\n']);
+    printf!("\n");
 }
 
 /// Finds the path of an executable named \p cmd, by looking in $PATH taken from \p vars.

fish-rust/src/proc.rs

@@ -1772,7 +1772,7 @@ fn process_clean_after_marking(parser: &Parser, allow_interactive: bool) -> bool
     }
 
     if printed {
-        let _ = std::io::stdout().lock().flush();
+        let _ = std::io::stdout().flush();
     }
 
     printed