chore: apply clippy lint suggestions

warning: redundant field names in struct initialization
   --> src/cmd/validate.rs:371:13
    |
371 |             cache_age_secs: cache_age_secs,
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `cache_age_secs`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#redundant_field_names
    = note: `#[warn(clippy::redundant_field_names)]` on by default

warning: redundant field names in struct initialization
   --> src/cmd/validate.rs:375:13
    |
375 |             ckan_token: ckan_token,
    |             ^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `ckan_token`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#redundant_field_names

warning: using `clone` on type `Option<Delimiter>` which implements the `Copy` trait
   --> src/cmd/validate.rs:362:13
    |
362 |             delim.clone()
    |             ^^^^^^^^^^^^^ help: try dereferencing it: `*delim`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#clone_on_copy
    = note: `#[warn(clippy::clone_on_copy)]` on by default

warning: the borrowed expression implements the required traits
  --> src/lookup.rs:43:41
   |
43 |         let expanded_dir = expand_tilde(&cache_dir).unwrap();
   |                                         ^^^^^^^^^^ help: change this to: `cache_dir`
   |
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_borrows_for_generic_args
   = note: `#[warn(clippy::needless_borrows_for_generic_args)]` on by default

src/cmd/validate.rs

@@ -359,7 +359,7 @@ fn dyn_enum_validator_factory<'a>(
         };
 
         let delimiter = if let Some(delim) = DELIMITER.get() {
-            delim.clone()
+            *delim
         } else {
             None
         };
@@ -368,11 +368,11 @@ fn dyn_enum_validator_factory<'a>(
         let opts = LookupTableOptions {
             name: lookup_name,
             uri: uri.clone(),
-            cache_age_secs: cache_age_secs,
+            cache_age_secs,
             cache_dir: QSV_CACHE_DIR.get().unwrap().to_string(),
             delimiter,
             ckan_api_url: CKAN_API.get().cloned(),
-            ckan_token: ckan_token,
+            ckan_token,
             timeout_secs: TIMEOUT_SECS.load(Ordering::Relaxed),
         };
 

src/lookup.rs

@@ -40,7 +40,7 @@ pub fn set_qsv_cache_dir(cache_dir: &str) -> Result<String, CliError> {
         }
     } else if cache_dir.starts_with('~') {
         // expand the tilde
-        let expanded_dir = expand_tilde(&cache_dir).unwrap();
+        let expanded_dir = expand_tilde(cache_dir).unwrap();
         expanded_dir.to_string_lossy().to_string()
     } else {
         cache_dir.to_string()