drm/ttm: use shmem_read_mapping_page

drm/ttm: use shmem_read_mapping_page

Soon tmpfs will stop supporting ->readpage and read_mapping_page(): once
"tmpfs: add shmem_read_mapping_page_gfp" has been applied, this patch can
be applied to ease the transition.

ttm_tt_swapin() and ttm_tt_swapout() use shmem_read_mapping_page() in
place of read_mapping_page(), since their swap_space has been created with
shmem_file_setup().

Signed-off-by: Hugh Dickins <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Thomas Hellstrom <[email protected]>
Cc: Dave Airlie <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>