mtd,ubi,ubifs: sync with linux v3.15

snyc with linux v3.15:

commit 1860e379875dfe7271c649058aeddffe5afd9d0d
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date:   Sun Jun 8 11:19:54 2014 -0700

    Linux 3.15

Signed-off-by: Heiko Schocher <hs@denx.de>
Cc: Scott Wood <scottwood@freescale.com>
Cc: Tom Rini <trini@ti.com>
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index 5f53691..dd9b668 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -531,7 +531,7 @@
 	dbg_gen("inode %lu, mode %#x", inode->i_ino, (int)inode->i_mode);
 	ubifs_assert(!atomic_read(&inode->i_count));
 
-	truncate_inode_pages(&inode->i_data, 0);
+	truncate_inode_pages_final(&inode->i_data);
 
 	if (inode->i_nlink)
 		goto done;
@@ -1786,7 +1786,7 @@
 	if (c->space_fixup) {
 		err = ubifs_fixup_free_space(c);
 		if (err)
-			return err;
+			goto out;
 	}
 
 	err = check_free_space(c);
@@ -2063,6 +2063,7 @@
 	int err;
 	struct ubifs_info *c = sb->s_fs_info;
 
+	sync_filesystem(sb);
 	dbg_gen("old flags %#lx, new flags %#x", sb->s_flags, *flags);
 
 	err = ubifs_parse_options(c, data, 1);