ubifs: remove useless code

By checking ubifs source code, s_instances parameter is not
used anymore. So, set this parameter and the associated source
code under __UBOOT__ compilation.

Signed-off-by: Christophe Kerello <christophe.kerello@st.com>
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index abdef1e..9603163 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -2360,7 +2360,9 @@
 		return ERR_PTR(err);
 	}
 
+#ifndef __UBOOT__
 	INIT_HLIST_NODE(&s->s_instances);
+#endif
 	INIT_LIST_HEAD(&s->s_inodes);
 	s->s_time_gran = 1000000000;
 	s->s_flags = flags;
@@ -2429,14 +2431,12 @@
 #ifndef __UBOOT__
 	strlcpy(s->s_id, type->name, sizeof(s->s_id));
 	list_add_tail(&s->s_list, &super_blocks);
-#else
-	strncpy(s->s_id, type->name, sizeof(s->s_id));
-#endif
 	hlist_add_head(&s->s_instances, &type->fs_supers);
-#ifndef __UBOOT__
 	spin_unlock(&sb_lock);
 	get_filesystem(type);
 	register_shrinker(&s->s_shrink);
+#else
+	strncpy(s->s_id, type->name, sizeof(s->s_id));
 #endif
 	return s;
 }