drivers/staging: make android lowmemorykiller.c explicitly non-modular

The Kconfig currently controlling compilation of this code is:

drivers/staging/android/Kconfig:config ANDROID_LOW_MEMORY_KILLER
drivers/staging/android/Kconfig:        bool "Android Low Memory Killer"

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

Lets remove the modular code that is essentially orphaned, so that
when reading the driver there is no doubt it is builtin-only.

Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.

We replace module.h with init.h and moduleparam.h ; the latter since
this file was previously implicitly relying on getting that header.

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

Cc: "Arve Hjønnevåg" <arve@android.com>
Cc: Riley Andrews <riandrews@android.com>
Cc: devel@driverdev.osuosl.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/android/lowmemorykiller.c

@@ -32,7 +32,8 @@
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
-#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/moduleparam.h>
 #include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/oom.h>
@@ -190,12 +191,12 @@ static int __init lowmem_init(void)
 	register_shrinker(&lowmem_shrinker);
 	return 0;
 }
+device_initcall(lowmem_init);
 
-static void __exit lowmem_exit(void)
-{
-	unregister_shrinker(&lowmem_shrinker);
-}
-
+/*
+ * not really modular, but the easiest way to keep compat with existing
+ * bootargs behaviour is to continue using module_param here.
+ */
 module_param_named(cost, lowmem_shrinker.seeks, int, S_IRUGO | S_IWUSR);
 module_param_array_named(adj, lowmem_adj, short, &lowmem_adj_size,
 			 S_IRUGO | S_IWUSR);
@@ -203,8 +204,3 @@ module_param_array_named(minfree, lowmem_minfree, uint, &lowmem_minfree_size,
 			 S_IRUGO | S_IWUSR);
 module_param_named(debug_level, lowmem_debug_level, uint, S_IRUGO | S_IWUSR);
 
-module_init(lowmem_init);
-module_exit(lowmem_exit);
-
-MODULE_LICENSE("GPL");
-