LU-8633 llite: do not clear uptodate bit in page delete

LU-8633 llite: do not clear uptodate bit in page delete

Otherwise, if the race between page fault and truncate occurs, it
will cause the page fault routine to return an EIO error.

In filemap_fault() {
    page_not_uptodate:
	...
        ClearPageError(page);
        error = mapping->a_ops->readpage(file, page);
        if (!error) {
                wait_on_page_locked(page);
                if (!PageUptodate(page))
                        error = -EIO;
	}
	...
}

However, I tend to think this is a defect in kernel implementation,
because it assumes PageUptodate shouldn't be cleared but file read
routine doesn't make the same assumption.

Signed-off-by: Jinshan Xiong <jinshan.xiong@intel.com>
Change-Id: Ic4a919607a6121098e41eaf56b8ce3200f778ecf
Reviewed-on: http://review.whamcloud.com/22827
Tested-by: Maloo <hpdd-maloo@intel.com>
Tested-by: Jenkins
Reviewed-by: Li Dongyang <dongyang.li@anu.edu.au>
Reviewed-by: Bobi Jam <bobijam@hotmail.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>