EX-6841 tests: do not truncate over s_maxbytes

EX-6841 tests: do not truncate over s_maxbytes

sanity-lipe-scan3/104 truncates file to MAX_LFS_FILESIZE
but it should not go over s_maxbytes.

Fixes: c05dbbbbca ("EX-4015 lipe: add lipe_scan3")
Test-Parameters: trivial testlist=sanity-lipe-scan3 env=ONLY=104
Change-Id: I4a14befb0dfc34b2611052850b77a0841ff853aa
Signed-off-by: Li Dongyang <dongyangli@ddn.com>
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/50899
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Alexandre Ioffe <aioffe@ddn.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>