address latest clippy warnings (#679)

src/agent/onefuzz-agent/src/tasks/fuzz/supervisor.rs

@@ -260,7 +260,7 @@ mod tests {
         let runtime_dir = tempfile::tempdir().unwrap();
 
         let supervisor_exe = if let Ok(x) = env::var("ONEFUZZ_TEST_AFL_LINUX_FUZZER") {
-            x.into()
+            x
         } else {
             warn!("Unable to test AFL integration");
             return;

src/agent/onefuzz-agent/src/tasks/generic/input_poller/tests.rs

@@ -100,9 +100,7 @@ fn url_input_name(url: &Url) -> String {
 }
 
 fn fixture() -> InputPoller<Msg> {
-    let task = InputPoller::new();
-
-    task
+    InputPoller::new()
 }
 
 fn url_fixture(msg: Msg) -> Url {