f - fix test under c_bindings

Author: jkczyz

lightning/src/offers/invoice_request.rs

@@ -2254,7 +2254,7 @@ mod tests {
 		let secp_ctx = Secp256k1::new();
 
 		#[cfg(c_bindings)]
-		use super::OfferWithDerivedMetadataBuilder as OfferBuilder;
+		use crate::offers::offer::OfferWithDerivedMetadataBuilder as OfferBuilder;
 		let offer = OfferBuilder
 			::deriving_signing_pubkey(desc, node_id, &expanded_key, &entropy, &secp_ctx)
 			.chain(Network::Testnet)