Cleanup.

src/cli.rs

@@ -31,14 +31,16 @@ pub struct Args {
     #[arg(short, long, default_value_t = crate::FB_SECTOR_SIZE)]
     pub sector_size: usize,
 
-    // Behaviour is backwards.
+    // !!! ArgAction behaviour is backwards !!!
     // ArgAction::SetFalse by default evaluates to true,
     // ArgAction::SetTrue by default evaluates to false.
+    //
     /// Upon encountering a read error, reopen the source file before continuing.
     #[arg(short, long, action = ArgAction::SetTrue)]
     pub reopen_on_error: bool,
 
     /// Use O_DIRECT to bypass kernel buffer when reading.
+    //
     // BSD seems to support O_DIRECT, but MacOS for certain does not.
     #[cfg(all(unix, not(target_os = "macos")))]
     #[arg(short, long = "direct", action = ArgAction::SetFalse)]