LUDOC-11 lfs: use a more realistic PFL layout

LUDOC-11 lfs: use a more realistic PFL layout

Don't use an example for "lfs setstripe" that explicitly sets an
index of 0, since this will cause an imbalance in the OST usage,
and is not a good example for users to follow.

Create the PFL layout with a more typical configuration.

Signed-off-by: Andreas Dilger <adilger@whamcloud.com>
Change-Id: Ic7ca6d1b25760d1292c7ac2cfb3c11497c2efa52
Reviewed-on: https://review.whamcloud.com/33367
Tested-by: Jenkins
Reviewed-by: Joseph Gmitter <jgmitter@whamcloud.com>