It is essential that the function path always go through EXIT_MODULE(). The easiest way to ensure that EXIT_MODULE() is called before exiting is to have only one exit point from the function.
On the error return from wn_up(), a jump was made to END:, rather than making an immediate return. Although in a simple function it may be preferable to avoid the goto, when you want a single exit from a complex function, the goto can simplify and improve readability of your code.
