UBI: set correct gluebi device size

In case of static volumes, make emulated MTD device size to
be equivalent to data size, rather then volume size.

Reported-by: John Smith <john@arrows.demon.co.uk>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
diff --git a/drivers/mtd/ubi/scan.c b/drivers/mtd/ubi/scan.c
index 30d536e..197cd650 100644
--- a/drivers/mtd/ubi/scan.c
+++ b/drivers/mtd/ubi/scan.c
@@ -55,7 +55,7 @@
 static struct ubi_ec_hdr *ech;
 static struct ubi_vid_hdr *vidh;
 
-/*
+/**
  * add_to_list - add physical eraseblock to a list.
  * @si: scanning information
  * @pnum: physical eraseblock number to add