Move link doc of printk related modules to README

kernel_module/README.adoc

@@ -1,14 +1,10 @@
 = kernel_module
 
-. link:module_init.c[]
-. Debugging
-.. link:hello.c[]
-.. link:hello2.c[]
-.. link:printk.c[]
 . Modules
 .. link:params.c[]
 .. link:vermagic.c[]
 .. link:vermagic_fail.c[]
+.. link:module_init.c[]
 .. link:module_info.c[]
 .. Module dependencies
 ... link:dep.c[]

kernel_module/hello.c

@@ -1,12 +1,4 @@
-/*
-Hello world module.
-
-	dmesg -c
-	insmod hello.ko
-	dmesg -c | grep 'hello init'
-	rmmod hello.ko
-	dmesg -c | grep 'hello exit'
-*/
+/* https://github.com/cirosantilli/linux-kernel-module-cheat#getting-started-natively */
 
 #include <linux/module.h>
 #include <linux/kernel.h>

kernel_module/hello2.c

@@ -1,8 +1,4 @@
-/*
-Hello world module 2.
-
-Mostly to check that our build infrastructure can handle more than one module!
-*/
+/* https://github.com/cirosantilli/linux-kernel-module-cheat#getting-started-natively */
 
 #include <linux/module.h>
 #include <linux/kernel.h>

kernel_module/myprintk.c

@@ -1,3 +1,5 @@
+/* https://github.com/cirosantilli/linux-kernel-module-cheat#pr_debug */
+
 #include <linux/module.h>
 #include <linux/kernel.h>