get rid of lkmc package, move userland and kernel-modules to top

Rationale: we already had a non buildroot build system,
maintaining both will be hard, and having short paths is more awesome.

kernel_modules/seq_file_single_open.c

@@ -0,0 +1,46 @@
+/* https://github.com/cirosantilli/linux-kernel-module-cheat#seq_file-single_open */
+
+#include <linux/debugfs.h>
+#include <linux/errno.h> /* EFAULT */
+#include <linux/fs.h>
+#include <linux/module.h>
+#include <linux/printk.h> /* pr_info */
+#include <linux/seq_file.h> /* seq_read, seq_lseek, single_release */
+#include <linux/uaccess.h> /* copy_from_user, copy_to_user */
+#include <uapi/linux/stat.h> /* S_IRUSR */
+
+static struct dentry *debugfs_file;
+
+static int show(struct seq_file *m, void *v)
+{
+	seq_printf(m, "ab\ncd\n");
+	return 0;
+}
+
+static int open(struct inode *inode, struct file *file)
+{
+	return single_open(file, show, NULL);
+}
+
+static const struct file_operations fops = {
+	.llseek = seq_lseek,
+	.open = open,
+	.owner = THIS_MODULE,
+	.read = seq_read,
+	.release = single_release,
+};
+
+static int myinit(void)
+{
+	debugfs_file = debugfs_create_file("lkmc_seq_file_single_open", S_IRUSR, NULL, NULL, &fops);
+	return 0;
+}
+
+static void myexit(void)
+{
+	debugfs_remove(debugfs_file);
+}
+
+module_init(myinit)
+module_exit(myexit)
+MODULE_LICENSE("GPL");