lib/test_sort.c: make it explicitly non-modular

The Kconfig currently controlling compilation of this code is:

     lib/Kconfig.debug:config TEST_SORT
     lib/Kconfig.debug:      bool "Array-based sort test"

...meaning that it currently is not being built as a module by anyone.

Lets remove the couple traces of modular infrastructure use, so that
when reading the code there is no doubt it is builtin-only.

Since module_init translates to device_initcall in the non-modular case,
the init ordering becomes slightly earlier when we change it to use
subsys_initcall as done here.  However, since it is a self contained
test, this shouldn't be an issue and subsys_initcall seems like a better
fit for this particular case.

We also delete the MODULE_LICENSE tag since that information is now
contained at the top of the file in the comments.

Link: http://lkml.kernel.org/r/20170124225608.7319-1-paul.gortmaker@windriver.com
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Kostenzer Felix <fkostenzer@live.at>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/test_sort.c

@@ -1,8 +1,11 @@
 #include <linux/sort.h>
 #include <linux/slab.h>
-#include <linux/module.h>
+#include <linux/init.h>
 
-/* a simple boot-time regression test */
+/*
+ * A simple boot-time regression test
+ * License: GPL
+ */
 
 #define TEST_LEN 1000
 
@@ -38,6 +41,4 @@ exit:
 	kfree(a);
 	return err;
 }
-
-module_init(test_sort_init);
-MODULE_LICENSE("GPL");
+subsys_initcall(test_sort_init);