refactoring: remove unnecessary references

src/error.rs

@@ -12,11 +12,11 @@ pub enum ShellError {
 impl PartialEq<Self> for ShellError {
     fn eq(&self, other: &Self) -> bool {
         match self {
-            &ShellError::EmptyLine => matches!(other, ShellError::EmptyLine),
-            &ShellError::NotFound(_) => matches!(other, ShellError::NotFound(_)),
-            &ShellError::ExecuteFailure(_) => matches!(other, ShellError::ExecuteFailure(_)),
-            &ShellError::MalformedArgs(_) => matches!(other, ShellError::MalformedArgs(_)),
-            &ShellError::Interrupt => matches!(other, ShellError::Interrupt),
+            ShellError::EmptyLine => matches!(other, ShellError::EmptyLine),
+            ShellError::NotFound(_) => matches!(other, ShellError::NotFound(_)),
+            ShellError::ExecuteFailure(_) => matches!(other, ShellError::ExecuteFailure(_)),
+            ShellError::MalformedArgs(_) => matches!(other, ShellError::MalformedArgs(_)),
+            ShellError::Interrupt => matches!(other, ShellError::Interrupt),
         }
     }
 }