apply some style fix from clippy

src/legacy.rs

diff --git a/src/legacy.rs b/src/legacy.rs
index 1ccfef1..d55f3a1 100644
--- a/src/legacy.rs
+++ b/src/legacy.rs
@@ -94,13 +94,7 @@
         elements += 1;
     }
 
-    Ok((
-        Demangle {
-            inner: inner,
-            elements: elements,
-        },
-        chars.as_str(),
-    ))
+    Ok((Demangle { inner, elements }, chars.as_str()))
 }
 
 // Rust hashes are hex digits with an `h` prepended.
@@ -142,7 +136,7 @@
                     }
                 } else if rest.starts_with('$') {
                     let (escape, after_escape) = if let Some(end) = rest[1..].find('$') {
-                        (&rest[1..end + 1], &rest[end + 2..])
+                        (&rest[1..=end], &rest[end + 2..])
                     } else {
                         break;
                     };

src/lib.rs

diff --git a/src/lib.rs b/src/lib.rs
index 49ec429..2b8684e 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -97,7 +97,7 @@
     // Output like LLVM IR adds extra period-delimited words. See if
     // we are in that case and save the trailing words if so.
     if !suffix.is_empty() {
-        if suffix.starts_with(".") && is_symbol_like(suffix) {
+        if suffix.starts_with('.') && is_symbol_like(suffix) {
             // Keep the suffix.
         } else {
             // Reset the suffix and invalidate the demangling.
@@ -107,9 +107,9 @@
     }
 
     Demangle {
-        style: style,
+        style,
         original: s,
-        suffix: suffix,
+        suffix,
     }
 }
 

src/v0.rs

diff --git a/src/v0.rs b/src/v0.rs
index e83a220..7fd0cf1 100644
--- a/src/v0.rs
+++ b/src/v0.rs
@@ -19,7 +19,7 @@
     let inner;
     if s.len() > 2 && s.starts_with("_R") {
         inner = &s[2..];
-    } else if s.len() > 1 && s.starts_with("R") {
+    } else if s.len() > 1 && s.starts_with('R') {
         // On Windows, dbghelp strips leading underscores, so we accept "R..."
         // form too.
         inner = &s[1..];
@@ -56,7 +56,7 @@
         _ => {}
     }
 
-    Ok((Demangle { inner: inner }, &parser.sym[parser.next..]))
+    Ok((Demangle { inner }, &parser.sym[parser.next..]))
 }
 
 impl<'s> Display for Demangle<'s> {