LU-14094 tests: give zfs more wait time to unlink

LU-14094 tests: give zfs more wait time to unlink

In sanity.sh test_311, give zfs more wait time to unlink more
files as expected.

Test-Parameters: trivial fstype=zfs testlist=sanity env=ONLY=311,ONLY_REPEAT=200
Test-Parameters: trivial fstype=zfs testlist=sanity env=ONLY=311,ONLY_REPEAT=200
Test-Parameters: trivial fstype=zfs testlist=sanity env=ONLY=311,ONLY_REPEAT=200
Test-Parameters: trivial fstype=zfs testlist=sanity env=ONLY=311,ONLY_REPEAT=200
Test-Parameters: trivial fstype=zfs testlist=sanity env=ONLY=311,ONLY_REPEAT=200
Signed-off-by: Emoly Liu <emoly@whamcloud.com>
Change-Id: I17f278df3826fa38b71713c610d644cc7676c1ad
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/56952
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Mikhail Pershin <mpershin@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>