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/process.c b/arch/um/kernel/process.c
index e8cb9ff..83603cf 100644
--- a/arch/um/kernel/process.c
+++ b/arch/um/kernel/process.c
@@ -364,7 +364,7 @@
 	if (!sysemu_supported)
 		return 0;
 
-	ent = create_proc_entry("sysemu", 0600, &proc_root);
+	ent = create_proc_entry("sysemu", 0600, NULL);
 
 	if (ent == NULL)
 	{