UBIFS: add inode size debugging check

Add one more check to UBIFS - a check that makes sure that there
are no data nodes beyond inode size. And few commantaries fixes
along the line.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Reviewed-by: Adrian Hunter <Adrian.Hunter@nokia.com>
diff --git a/fs/ubifs/debug.h b/fs/ubifs/debug.h
index c1cd73b..fe2c927 100644
--- a/fs/ubifs/debug.h
+++ b/fs/ubifs/debug.h
@@ -321,6 +321,8 @@
 int dbg_check_lprops(struct ubifs_info *c);
 int dbg_check_lpt_nodes(struct ubifs_info *c, struct ubifs_cnode *cnode,
 			int row, int col);
+int dbg_check_inode_size(struct ubifs_info *c, const struct inode *inode,
+			 loff_t size);
 
 /* Force the use of in-the-gaps method for testing */
 
@@ -460,6 +462,7 @@
 #define dbg_check_heap(c, heap, cat, add_pos)      ({})
 #define dbg_check_lprops(c)                        0
 #define dbg_check_lpt_nodes(c, cnode, row, col)    0
+#define dbg_check_inode_size(c, inode, size)       0
 #define dbg_force_in_the_gaps_enabled              0
 #define dbg_force_in_the_gaps()                    0
 #define dbg_failure_mode                           0