LU-11667 tests: Fix sanity test 317 for 64K PAGE_SIZE OST

LU-11667 tests: Fix sanity test 317 for 64K PAGE_SIZE OST

When create a file, blocks are allocated with PAGE_SIZE aligned,
see function osd_ldiskfs_map_inode_pages(). E.g. for 64K PAGE_SIZE
Arm64 OST server, if create a file with size less than 64K, it
actually allocates 128 blocks each block 512 Bytes.

It needs to adjust the test for 64K PAGE_SIZE OST server.

Lustre-change: https://review.whamcloud.com/45395
Lustre-commit: 63d4d9ff2f5c8cc992ca6b2f698bb43a3257bfb3

Test-Parameters: trivial
Test-Parameters: clientdistro=el8.5 clientarch=aarch64 fstype=ldiskfs testlist=sanity \
env=PTLDEBUG=-1,ONLY=317
Test-Parameters: fstype=ldiskfs testlist=sanity \
env=PTLDEBUG=-1,ONLY=317

Change-Id: Iada701f4f424093e847fc70aa843873b75fe6b06
Signed-off-by: Xinliang Liu <xinliang.liu@linaro.org>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Reviewed-on: https://review.whamcloud.com/46482
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>