UBIFS: fix memory leak on error path

UBIFS leaks memory on error path in 'mount_ubifs()'. In case of failure in
'ubifs_fixup_free_space()', it does not call 'ubifs_lpt_free()' whereas LPT
data structures can potentially be allocated. The amount of memory leaked can
be quite high -- see 'ubifs_lpt_init()'.

The bug was introduced when moving the LPT initialisation earlier in the
mount process (commit '781c5717').
Signed-off-by: Sidney Amani <seed95@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>

fs/ubifs/super.c

@@ -1301,7 +1301,7 @@ static int mount_ubifs(struct ubifs_info *c)
 	if (!c->ro_mount && c->space_fixup) {
 		err = ubifs_fixup_free_space(c);
 		if (err)
-			goto out_master;
+			goto out_lpt;
 	}
 
 	if (!c->ro_mount) {