Prevent memoryleak in stabilizeScreenBackground.

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@4173 dfc29bdd-3216-0410-991c-e03cc46cb475

tests/testUtils.cpp

@@ -376,7 +376,11 @@ void stabilizeScreenBackground(irr::video::IVideoDriver * driver,
 		}
 
 		if(status)
+		{
+			screenshot->drop();
 			return;
+		}
+		screenshot->drop();
 	}
 }