If the backing_dev_info doesn't have BDI_CAP_NO_WRITEBACK we're not supposed
to write back an inode's pages.  But in this situation write_inode_now()
refuses to write the inode itself as well.  Fix.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>