UBI: rename struct ubi_scan_leb

Rename 'struct ubi_scan_leb' to 'struct ubi_ainf_leb'. This is part
of the code re-structuring I am trying to do in order to add fastmap
in a more logical way. Fastmap can share a lot with scanning, including
the attach-time data structures, which all now have "scan" word in the
name. Let's get rid of this word and use "ainf" instead which stands
for "attach information". It has the same length as "scan" so re-naming
is trivial.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@linux.intel.com>

drivers/mtd/ubi/wl.c

@@ -1385,7 +1385,7 @@ int ubi_wl_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si)
 	int err, i;
 	struct rb_node *rb1, *rb2;
 	struct ubi_scan_volume *sv;
-	struct ubi_scan_leb *seb, *tmp;
+	struct ubi_ainf_peb *seb, *tmp;
 	struct ubi_wl_entry *e;
 
 	ubi->used = ubi->erroneous = ubi->free = ubi->scrub = RB_ROOT;