fix clippy errors

Signed-off-by: Ryan Tate <[email protected]>

src/core/credential_format/mod.rs

@@ -292,6 +292,6 @@ impl From<&CredentialType> for String {
 
 impl std::fmt::Display for &CredentialType {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        write!(f, "{}", self)
+        write!(f, "{}", String::from(*self))
     }
 }