refactor/polish ~ fix cargo clippy complaints (default/tests => let ... = if ...)

src/nl/nl.rs

@@ -333,10 +333,9 @@ fn nl<T: Read>(reader: &mut BufReader<T>, settings: &Settings) {
         // way, start counting empties from zero once more.
         empty_line_count = 0;
         // A line number is to be printed.
-        let mut w: usize = 0;
-        if settings.number_width > line_no_width {
-            w = settings.number_width - line_no_width;
-        }
+        let w = if settings.number_width > line_no_width {
+            settings.number_width - line_no_width
+        } else { 0 };
         let fill: String = repeat(fill_char).take(w).collect();
         match settings.number_format {
             NumberFormat::Left => println!(

src/pathchk/pathchk.rs

@@ -86,11 +86,10 @@ pub fn uumain(args: Vec<String>) -> i32 {
             0
         }
         _ => {
-            let mut res = true;
-            if matches.free.len() == 0 {
+            let mut res = if matches.free.is_empty() {
                 show_error!("missing operand\nTry {} --help for more information", NAME);
-                res = false;
-            }
+                false
+            } else { true };
             // free strings are path operands
             // FIXME: TCS, seems inefficient and overly verbose (?)
             for p in matches.free {

src/printf/tokenize/unescaped_text.rs

@@ -60,11 +60,10 @@ impl UnescapedText {
     // dropped-in as a replacement.
     fn validate_iec(val: u32, eight_word: bool) {
         let mut preface = 'u';
-        let mut leading_zeros = 4;
-        if eight_word {
+        let leading_zeros = if eight_word {
             preface = 'U';
-            leading_zeros = 8;
-        }
+            8
+        } else { 4 };
         let err_msg = format!(
             "invalid universal character name {0}{1:02$x}",
             preface, val, leading_zeros

src/readlink/readlink.rs

@@ -70,18 +70,13 @@ pub fn uumain(args: Vec<String>) -> i32 {
     let silent = matches.opt_present("silent") || matches.opt_present("quiet");
     let verbose = matches.opt_present("verbose");
 
-    let mut can_mode = CanonicalizeMode::None;
-    if matches.opt_present("canonicalize") {
-        can_mode = CanonicalizeMode::Normal;
-    }
-
-    if matches.opt_present("canonicalize-existing") {
-        can_mode = CanonicalizeMode::Existing;
-    }
-
-    if matches.opt_present("canonicalize-missing") {
-        can_mode = CanonicalizeMode::Missing;
-    }
+    let can_mode = if matches.opt_present("canonicalize") {
+        CanonicalizeMode::Normal
+    } else if matches.opt_present("canonicalize-existing") {
+        CanonicalizeMode::Existing
+    } else if matches.opt_present("canonicalize-missing") {
+        CanonicalizeMode::Missing
+    } else { CanonicalizeMode::None };
 
     let files = matches.free;
     if files.is_empty() {