proc: remove proc_root from drivers

Remove proc_root export.  Creation and removal works well if parent PDE is
supplied as NULL -- it worked always that way.

So, one useless export removed and consistency added, some drivers created
PDEs with &proc_root as parent but removed them as NULL and so on.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/um/kernel/exitcode.c b/arch/um/kernel/exitcode.c
index 984f80e..6540d2c 100644
--- a/arch/um/kernel/exitcode.c
+++ b/arch/um/kernel/exitcode.c
@@ -59,7 +59,7 @@
 {
 	struct proc_dir_entry *ent;
 
-	ent = create_proc_entry("exitcode", 0600, &proc_root);
+	ent = create_proc_entry("exitcode", 0600, NULL);
 	if (ent == NULL) {
 		printk(KERN_WARNING "make_proc_exitcode : Failed to register "
 		       "/proc/exitcode\n");