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/drivers/s390/block/dasd_proc.c b/drivers/s390/block/dasd_proc.c
index 556063e..8ae9406 100644
--- a/drivers/s390/block/dasd_proc.c
+++ b/drivers/s390/block/dasd_proc.c
@@ -311,7 +311,7 @@
 int
 dasd_proc_init(void)
 {
-	dasd_proc_root_entry = proc_mkdir("dasd", &proc_root);
+	dasd_proc_root_entry = proc_mkdir("dasd", NULL);
 	if (!dasd_proc_root_entry)
 		goto out_nodasd;
 	dasd_proc_root_entry->owner = THIS_MODULE;
@@ -335,7 +335,7 @@
  out_nostatistics:
 	remove_proc_entry("devices", dasd_proc_root_entry);
  out_nodevices:
-	remove_proc_entry("dasd", &proc_root);
+	remove_proc_entry("dasd", NULL);
  out_nodasd:
 	return -ENOENT;
 }
@@ -345,5 +345,5 @@
 {
 	remove_proc_entry("devices", dasd_proc_root_entry);
 	remove_proc_entry("statistics", dasd_proc_root_entry);
-	remove_proc_entry("dasd", &proc_root);
+	remove_proc_entry("dasd", NULL);
 }