f construct_payment_secret cleanups

Author: valentinewallace

lightning/src/ln/channelmanager.rs

@@ -189,16 +189,14 @@ mod inbound_payment {
 		Ok(metadata_bytes)
 	}
 
-	fn construct_payment_secret(iv_bytes: &[u8; IV_LEN], metadata_bytes: &[u8], metadata_key: &[u8; METADATA_KEY_LEN]) -> PaymentSecret {
+	fn construct_payment_secret(iv_bytes: &[u8; IV_LEN], metadata_bytes: &[u8; METADATA_LEN], metadata_key: &[u8; METADATA_KEY_LEN]) -> PaymentSecret {
 		let mut payment_secret_bytes: [u8; 32] = [0; 32];
-		{
-			let (iv_slice, encrypted_metadata_slice) = payment_secret_bytes.split_at_mut(IV_LEN);
-			iv_slice.copy_from_slice(iv_bytes);
+		let (iv_slice, encrypted_metadata_slice) = payment_secret_bytes.split_at_mut(IV_LEN);
+		iv_slice.copy_from_slice(iv_bytes);
 
-			let chacha_block = ChaCha20::get_single_block(metadata_key, iv_bytes);
-			for i in 0..METADATA_LEN {
-				encrypted_metadata_slice[i] = chacha_block[i] ^ metadata_bytes[i];
-			}
+		let chacha_block = ChaCha20::get_single_block(metadata_key, iv_bytes);
+		for i in 0..METADATA_LEN {
+			encrypted_metadata_slice[i] = chacha_block[i] ^ metadata_bytes[i];
 		}
 		PaymentSecret(payment_secret_bytes)
 	}