lib/test_sort.c: add module unload support

test_sort.c performs array-based and linked list sort test.  Code allows
to compile either as a loadable modules or builtin into the kernel.

Current code is not allow to unload the test_sort.ko module after
successful completion.

This patch adds support to unload the "test_sort.ko" module by adding
module_exit support.

Previous patch was implemented auto unload support by returning -EAGAIN
from module_init() function on successful case, but this approach is not
ideal.

The auto-unload might seem like a nice optimization, but it encourages
inconsistent behaviour.  And behaviour that is different from all other
normal modules.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Pravin Shedge <[email protected]>
Cc: Kostenzer Felix <[email protected]>
Cc: Andy Shevchenko <[email protected]>
Cc: Geert Uytterhoeven <[email protected]>
Cc: Paul Gortmaker <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

lib/test_sort.c

@@ -39,5 +39,11 @@ exit:
 	return err;
 }
 
+static void __exit test_sort_exit(void)
+{
+}
+
 module_init(test_sort_init);
+module_exit(test_sort_exit);
+
 MODULE_LICENSE("GPL");