UBIFS: run debugging checks only if they are enabled

Do not forget to check whether lpt debugging is enabled before
running the check functions. This commit also makes some spelling
fixes.

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

fs/ubifs/lpt.c

@@ -36,7 +36,7 @@
  * can be written into a single eraseblock. In that case, garbage collection
  * consists of just writing the whole table, which therefore makes all other
  * eraseblocks reusable. In the case of the big model, dirty eraseblocks are
- * selected for garbage collection, which consists are marking the nodes in
+ * selected for garbage collection, which consists of marking the clean nodes in
  * that LEB as dirty, and then only the dirty nodes are written out. Also, in
  * the case of the big model, a table of LEB numbers is saved so that the entire
  * LPT does not to be scanned looking for empty eraseblocks when UBIFS is first
@@ -156,7 +156,6 @@ int ubifs_calc_lpt_geom(struct ubifs_info *c)
 	}
 
 	c->check_lpt_free = c->big_lpt;
-
 	return 0;
 }