lib/test_vmalloc.c: drop empty exit function

The module is never loaded successfully.  Therefore, it'll never be
unloaded and we can remove the exit function.

Link: https://lkml.kernel.org/r/20240226191159.39509-3-martin@kaiser.cx
Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

lib/test_vmalloc.c

@@ -600,12 +600,7 @@ static int vmalloc_test_init(void)
 	return -EAGAIN; /* Fail will directly unload the module */
 }
 
-static void vmalloc_test_exit(void)
-{
-}
-
 module_init(vmalloc_test_init)
-module_exit(vmalloc_test_exit)
 
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Uladzislau Rezki");