mm: refactor truncate_complete_page()

mm: refactor truncate_complete_page()

Move call of delete_from_page_cache() and page->mapping check out of
truncate_complete_page() into the single caller - truncate_inode_page().
Also move page_mapped() check into truncate_complete_page().  That way
it will be easier to batch operations.

Also rename truncate_complete_page() to truncate_cleanup_page().

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Jan Kara <[email protected]>
Acked-by: Mel Gorman <[email protected]>
Reviewed-by: Andi Kleen <[email protected]>
Cc: Dave Chinner <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: "Kirill A. Shutemov" <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>