Adds Ternary Operator to Make Example Concise Issue reactjs#657

Author: michaelhiiva

content/docs/conditional-rendering.md

@@ -93,12 +93,9 @@ class LoginControl extends React.Component {
   render() {
     const isLoggedIn = this.state.isLoggedIn;
 
-    let button = null;
-    if (isLoggedIn) {
-      button = <LogoutButton onClick={this.handleLogoutClick} />;
-    } else {
-      button = <LoginButton onClick={this.handleLoginClick} />;
-    }
+    let button = isLoggedIn
+                 ? <LogoutButton onClick={this.handleLogoutClick} />
+                 : <LoginButton onClick={this.handleLoginClick} />;
 
     return (
       <div>