When cancelling the bootloader installation delete the bootloader install object.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@23222 a1c6a512-1295-4272-9138-f99709370657

rbutil/rbutilqt/rbutilqt.cpp

@@ -703,6 +703,7 @@ void RbUtilQt::installBootloader()
                     logger->close();
                     installBootloaderPost(true);
                 }
+                delete bl;
                 return;
         }
     }