http: remove variable redeclaration

In lib/_http_client.js, the variable `conn` was declared with the `var`
keyword three times in the same scope. This change eliminates the
variable entirely.

PR-URL: #4612
Reviewed-By: Michaël Zasso <mic.besace@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

Author: Trott

lib/_http_client.js

@@ -115,8 +115,7 @@ function ClientRequest(options, cb) {
   if (self.socketPath) {
     self._last = true;
     self.shouldKeepAlive = false;
-    var conn = self.agent.createConnection({ path: self.socketPath });
-    self.onSocket(conn);
+    self.onSocket(self.agent.createConnection({ path: self.socketPath }));
   } else if (self.agent) {
     // If there is an agent we should default to Connection:keep-alive,
     // but only if the Agent will actually reuse the connection!
@@ -135,12 +134,11 @@ function ClientRequest(options, cb) {
     self._last = true;
     self.shouldKeepAlive = false;
     if (options.createConnection) {
-      var conn = options.createConnection(options);
+      self.onSocket(options.createConnection(options));
     } else {
       debug('CLIENT use net.createConnection', options);
-      var conn = net.createConnection(options);
+      self.onSocket(net.createConnection(options));
     }
-    self.onSocket(conn);
   }
 
   self._deferToConnect(null, null, function() {