fix clippy: variables can be used directly in the format! string

Author: up9cloud

tests/testsuite/file_ini.rs

@@ -260,6 +260,8 @@ fn test_nothing() {
         .build();
     assert!(res.is_ok());
     let c = res.unwrap();
-    let cc = format!("{:?}", c);
-    assert_data_eq!(cc, str!("Config { defaults: {}, overrides: {}, sources: [], cache: Value { origin: None, kind: Table({}) } }"));
+    assert_data_eq!(
+        format!("{:?}", c),
+        str!("Config { defaults: {}, overrides: {}, sources: [], cache: Value { origin: None, kind: Table({}) } }")
+    );
 }

tests/testsuite/file_toml.rs

@@ -446,6 +446,8 @@ fn test_nothing() {
         .build();
     assert!(res.is_ok());
     let c = res.unwrap();
-    let cc = format!("{:?}", c);
-    assert_data_eq!(cc, str!("Config { defaults: {}, overrides: {}, sources: [], cache: Value { origin: None, kind: Table({}) } }"));
+    assert_data_eq!(
+        format!("{:?}", c),
+        str!("Config { defaults: {}, overrides: {}, sources: [], cache: Value { origin: None, kind: Table({}) } }")
+    );
 }

tests/testsuite/file_yaml.rs

@@ -414,6 +414,8 @@ fn test_nothing() {
         .build();
     assert!(res.is_ok());
     let c = res.unwrap();
-    let cc = format!("{:?}", c);
-    assert_data_eq!(cc, str!("Config { defaults: {}, overrides: {}, sources: [], cache: Value { origin: None, kind: Table({}) } }"));
+    assert_data_eq!(
+        format!("{:?}", c),
+        str!("Config { defaults: {}, overrides: {}, sources: [], cache: Value { origin: None, kind: Table({}) } }")
+    );
 }