rust: macros: remove helpers

Only one helper function (`expect_punct`) is used by our proc-macros. So
remove all others and move `expect_punct` into concat_idents.rs.

Signed-off-by: Benno Lossin <[email protected]>

Author: y86-dev

rust/macros/concat_idents.rs

@@ -2,15 +2,20 @@
 
 use proc_macro2::{token_stream, Ident, TokenStream, TokenTree};
 
-use crate::helpers::expect_punct;
-
 fn expect_ident(it: &mut token_stream::IntoIter) -> Ident {
     if let Some(TokenTree::Ident(ident)) = it.next() {
         ident
     } else {
         panic!("Expected Ident")
     }
 }
+fn expect_punct(it: &mut token_stream::IntoIter) -> char {
+    if let TokenTree::Punct(punct) = it.next().expect("Reached end of token stream for Punct") {
+        punct.as_char()
+    } else {
+        panic!("Expected Punct");
+    }
+}
 
 pub(crate) fn concat_idents(ts: TokenStream) -> TokenStream {
     let mut it = ts.into_iter();

rust/macros/helpers.rs

@@ -3,7 +3,6 @@
 //! Crate for all kernel procedural macros.
 
 mod concat_idents;
-mod helpers;
 mod module;
 mod paste;
 mod pin_data;