Refactor code based on clippy suggestions

src/ctr.rs

@@ -6,17 +6,15 @@ pub fn encrypt(key: &Bytes, nonce: u64, data: &Bytes) -> Bytes {
 }
 
 pub fn decrypt(Bytes(key): &Bytes, nonce: u64, Bytes(data): &Bytes) -> Bytes {
-    let mut counter: u64 = 0;
     let cipher_type = symm::Cipher::aes_128_ecb();
     let block_size = cipher_type.block_size();
     let mut result: Vec<u8> = vec![];
-    for cipher in data.chunks(block_size) {
+    for (counter, cipher) in (0_u64..).zip(data.chunks(block_size)) {
         let mut keyinput = nonce.to_le_bytes().to_vec();
         keyinput.append(&mut counter.to_le_bytes().to_vec());
         let keystream = crate::cbc::enrypt_aes_128_ecb_block(key, &keyinput);
-        let mut data = crate::utils::xor(&keystream, &cipher.to_vec());
+        let mut data = crate::utils::xor(&keystream, cipher);
         result.append(&mut data);
-        counter += 1;
     }
     Bytes(result)
 }