fix fmt

host-program/src/bin/add-go-prove.rs

@@ -86,7 +86,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
     match proving_result {
         Ok(Some(prover_result)) => {
             if execute_only2 == false {
-                log::info!("Generating proof successfully .The proof file and verifier contract are in the path {}.",&output_dir);
+                log::info!("Generating proof successfully .The proof file and verifier contract are in the path {}.", &output_dir);
                 let output_path = Path::new(&output_dir);
                 let proof_result_path = output_path.join("snark_proof_with_public_inputs.json");
                 let _ = file::new(&proof_result_path.to_string_lossy())
@@ -98,18 +98,20 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
                     .write(prover_result.solidity_verifier.as_slice());
             } else {
                 if prover_result.output_stream.len() == 0 {
-                    log::info!("output_stream.len() is too short: {}",prover_result.output_stream.len());
+                    log::info!("output_stream.len() is too short: {}", prover_result.output_stream.len());
                     return Ok(());
                 }
                 log::info!("Executing the guest program  successfully.");
-                let ret_data: Data = bincode::deserialize_from(prover_result.output_stream.as_slice())
-                .expect("deserialization failed");
+                let ret_data: Data =
+                    bincode::deserialize_from(prover_result.output_stream.as_slice())
+                    .expect("deserialization failed");
                 log::info!("ret_data: {:?}", ret_data);
             }
 
         }
         Ok(None) => {
             log::info!("Failed to generate proof.The result is None.");
+            return Ok(None);
         }
         Err(e) => {
             log::info!("Failed to generate proof. error: {}", e);