f cleanups

Author: valentinewallace

lightning/src/ln/channelmanager.rs

@@ -183,11 +183,8 @@ mod inbound_payment {
 		let expiry_bytes = (highest_seen_timestamp + invoice_expiry_delta_secs as u64 + 7200).to_be_bytes();
 
 		let mut metadata_bytes: [u8; METADATA_LEN] = [0; METADATA_LEN];
-		{
-			let (min_amt_msat_slice, expiry_slice) = metadata_bytes.split_at_mut(AMT_MSAT_LEN);
-			min_amt_msat_slice.copy_from_slice(&min_amt_msat_bytes);
-			expiry_slice.copy_from_slice(&expiry_bytes);
-		}
+		metadata_bytes[..AMT_MSAT_LEN].copy_from_slice(&min_amt_msat_bytes);
+		metadata_bytes[AMT_MSAT_LEN..].copy_from_slice(&expiry_bytes);
 
 		Ok(metadata_bytes)
 	}
@@ -256,7 +253,7 @@ mod inbound_payment {
 		amt_msat_bytes.copy_from_slice(&metadata_bytes[..AMT_MSAT_LEN]);
 		// Zero out the bits reserved to indicate the payment type.
 		amt_msat_bytes[0] &= 0b00011111;
-		let min_amt_msat = u64::from_be_bytes(amt_msat_bytes.try_into().unwrap());
+		let min_amt_msat: u64 = u64::from_be_bytes(amt_msat_bytes.into());
 		let expiry = u64::from_be_bytes(metadata_bytes[AMT_MSAT_LEN..].try_into().unwrap());
 
 		// Make sure to check to check the HMAC before doing the other checks below, to mitigate timing