Some clippy changes

client/src/client.rs

@@ -490,7 +490,7 @@ impl Client {
             e.security_mode == security_mode &&
                 e.security_policy_uri.as_ref() == security_policy_uri &&
                 url_matches(e.endpoint_url.as_ref(), &endpoint_url)
-        }).map(|e| e.clone());
+        }).cloned();
 
         // If something was found, return it, otherwise try a fuzzier match that ignores the hostname.
         if result.is_some() {
@@ -500,7 +500,7 @@ impl Client {
                 e.security_mode == security_mode &&
                     e.security_policy_uri.as_ref() == security_policy_uri &&
                     url_matches_except_host(e.endpoint_url.as_ref(), &endpoint_url)
-            }).map(|e| e.clone())
+            }).cloned()
         }
     }
 
@@ -543,7 +543,7 @@ impl Client {
             security_mode == e.security_mode &&
                 security_policy == SecurityPolicy::from_uri(e.security_policy_uri.as_ref()) &&
                 url_matches_except_host(endpoint_url, e.endpoint_url.as_ref())
-        }).map(|e| e.clone());
+        }).cloned();
 
         // Issue #16, #17 - the server may advertise an endpoint whose hostname is inaccessible
         // to the client so substitute the advertised hostname with the one the client supplied.

client/src/comms/tcp_transport.rs

@@ -116,7 +116,7 @@ impl WriteState {
     fn send_request(&mut self, request: SupportedMessage) -> Result<u32, StatusCode> {
         match connection_state!(self.state) {
             ConnectionState::Processing => {
-                let mut secure_channel = trace_write_lock_unwrap!(self.secure_channel);
+                let secure_channel = trace_read_lock_unwrap!(self.secure_channel);
                 let request_id = self.send_buffer.next_request_id();
                 self.send_buffer.write(request_id, request, &secure_channel)
             }

client/src/subscription_state.rs

@@ -42,7 +42,7 @@ impl SubscriptionState {
         if self.subscriptions.is_empty() {
             None
         } else {
-            Some(self.subscriptions.keys().map(|k| *k).collect())
+            Some(self.subscriptions.keys().cloned().collect())
         }
     }