ext3: copy i_flags to inode flags on write

Propagate flags such as S_APPEND, S_IMMUTABLE, etc.  from i_flags into
ext2-specific i_flags.  Hence, when someone sets these flags via a different
interface than ioctl, they are stored correctly.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>