LU-13703 utils: fix lfs_migrate with PFL arguments

LU-13703 utils: fix lfs_migrate with PFL arguments

Pass the '-c', '-S', and '--pool' options to "lfs migrate" when
they are part of a PFL component (after -E), rather than using
them to set the stripe_count and stripe_size of the whole file.

This precludes using '-A' and '-R' with explicitly specified PFL
file layouts, but that didn't make sense in the first place.

Fix the handling of "--pool <pool>" to use "-p <pool>" since
the script later only strips "-p " from the pool name.

Lustre-change: https://review.whamcloud.com/39145
Lustre-commit: 28597c233c980f53732ab7628c2ec38efbff5364

Test-Parameters: trivial
Fixes: 60c5bc25025 ("LU-8235 scripts: pass unrecognized options to lfs migrate")
Signed-off-by: Andreas Dilger <adilger@whamcloud.com>
Change-Id: Ib7fb6e08d81dbae77e8348fc5f09837c612540e5
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/49868
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>