ext3: fix mount option parsing

The "resize" option won't be noticed as it comes after the NULL option, so if
you try to mount (or in this case remount) with that option it won't be
recognized.

Signed-off-by: Josef Bacik <jbacik@redhat.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>