Fix cpplint errors

Fixes errors from the following categories:

- `readability/inheritance`
- `readability/braces`
- `readability/multiline_comment`
- `whitespace/newline`
- `whitespace/empty_if_body`
- `build/include_what_you_use`
- `build/header_guard`

Author: vkucera

PWGJE/Core/PWGJECoreLinkDef.h

@@ -9,8 +9,7 @@
 // granted to it by virtue of its status as an Intergovernmental Organization
 // or submit itself to any jurisdiction.
 
-#ifndef PWGJE_CORE_PWGJECORELINKDEF_H_
-#define PWGJE_CORE_PWGJECORELINKDEF_H_
+// NOLINT(build/header_guard)
 
 #pragma link off all globals;
 #pragma link off all classes;
@@ -21,5 +20,3 @@
 #pragma link C++ namespace jetutilities + ;
 #pragma link C++ namespace fastjetutilities + ;
 #pragma link C++ namespace jettaggingutilities + ;
-
-#endif // PWGJE_CORE_PWGJECORELINKDEF_H_