UBI: fix kernel-doc errors and warnings

No functional changes, just tweak comments to make kernel-doc
work fine and stop complaining.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
diff --git a/drivers/mtd/ubi/io.c b/drivers/mtd/ubi/io.c
index a84f0db..2fb64be 100644
--- a/drivers/mtd/ubi/io.c
+++ b/drivers/mtd/ubi/io.c
@@ -1101,8 +1101,7 @@
 }
 
 /**
- * paranoid_check_peb_ec_hdr - check that the erase counter header of a
- * physical eraseblock is in-place and is all right.
+ * paranoid_check_peb_ec_hdr - check erase counter header.
  * @ubi: UBI device description object
  * @pnum: the physical eraseblock number to check
  *
@@ -1180,8 +1179,7 @@
 }
 
 /**
- * paranoid_check_peb_vid_hdr - check that the volume identifier header of a
- * physical eraseblock is in-place and is all right.
+ * paranoid_check_peb_vid_hdr - check volume identifier header.
  * @ubi: UBI device description object
  * @pnum: the physical eraseblock number to check
  *