LU-3720 tests: use actual stripe count in sanity/130b

LU-3720 tests: use actual stripe count in sanity/130b

If the requested number of stripes is not created, then
the test will fail.  Use the actual number of stripes
when checking the filefrag output.

Also clean up code style in other test_130 subtests.

Test-Parameters: trivial testlist=sanity env=ONLY=130
Signed-off-by: Andreas Dilger <adilger@whamcloud.com>
Change-Id: Iec5926a2863c750d89f89a5cbf6bf5df0d3ebbe5
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/53072
Reviewed-by: Jian Yu <yujian@whamcloud.com>
Reviewed-by: Zhenyu Xu <bobijam@hotmail.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>