all: Use let-chains in Windows/Mac-specific code

Author: drinkcat

src/uu/ls/src/ls.rs

@@ -3398,11 +3398,11 @@ fn calculate_padding_collection(
     };
 
     for item in items {
-        if config.alloc_size {
-            if let Some(md) = item.get_metadata(&mut state.out) {
-                let block_size_len = display_size(get_block_size(md, config), config).len();
-                padding_collections.block_size = block_size_len.max(padding_collections.block_size);
-            }
+        if config.alloc_size
+            && let Some(md) = item.get_metadata(&mut state.out)
+        {
+            let block_size_len = display_size(get_block_size(md, config), config).len();
+            padding_collections.block_size = block_size_len.max(padding_collections.block_size);
         }
 
         let context_len = item.security_context.len();

src/uu/tail/src/tail.rs

@@ -213,17 +213,16 @@ fn tail_stdin(
     // on macOS and Linux.
     #[cfg(target_os = "macos")]
     {
-        if let Ok(mut stdin_handle) = Handle::stdin() {
-            if let Ok(meta) = stdin_handle.as_file_mut().metadata() {
-                if meta.file_type().is_dir() {
-                    set_exit_code(1);
-                    show_error!(
-                        "{}",
-                        translate!("tail-error-cannot-open-no-such-file", "file" => input.display_name.clone(), "error" => translate!("tail-no-such-file-or-directory"))
-                    );
-                    return Ok(());
-                }
-            }
+        if let Ok(mut stdin_handle) = Handle::stdin()
+            && let Ok(meta) = stdin_handle.as_file_mut().metadata()
+            && meta.file_type().is_dir()
+        {
+            set_exit_code(1);
+            show_error!(
+                "{}",
+                translate!("tail-error-cannot-open-no-such-file", "file" => input.display_name.clone(), "error" => translate!("tail-no-such-file-or-directory"))
+            );
+            return Ok(());
         }
     }
 

src/uu/wc/src/count_fast.rs

@@ -171,15 +171,15 @@ pub(crate) fn count_bytes_fast<T: WordCountable>(handle: &mut T) -> (usize, Opti
 
     #[cfg(windows)]
     {
-        if let Some(file) = handle.inner_file() {
-            if let Ok(metadata) = file.metadata() {
-                let attributes = metadata.file_attributes();
-
-                if (attributes & FILE_ATTRIBUTE_ARCHIVE) != 0
-                    || (attributes & FILE_ATTRIBUTE_NORMAL) != 0
-                {
-                    return (metadata.file_size() as usize, None);
-                }
+        if let Some(file) = handle.inner_file()
+            && let Ok(metadata) = file.metadata()
+        {
+            let attributes = metadata.file_attributes();
+
+            if (attributes & FILE_ATTRIBUTE_ARCHIVE) != 0
+                || (attributes & FILE_ATTRIBUTE_NORMAL) != 0
+            {
+                return (metadata.file_size() as usize, None);
             }
         }
     }