LU-10447 tests: deprecate $SETSTRIPE/$GETSTRIPE in sanity

LU-10447 tests: deprecate $SETSTRIPE/$GETSTRIPE in sanity

$SETSTRIPE and $GETSTRIPE were needed when we used the
standalone 'lstripe' utility. 'lstripe' hasn't been used
for years and we need to clean up all remnants of it.

Replace all instances of $SETSTRIPE with '$LFS setstripe'
and $GETSTRIPE with '$LFS getstripe' in the sanity and
sanityn test suites.

Test-Parameters: trivial testlist=sanityn
Signed-off-by: James Nunez <jnunez@whamcloud.com>
Change-Id: I492d261c7568634c8f0dd0d5a100ef5bb8433ad8
Reviewed-on: https://review.whamcloud.com/32809
Tested-by: Jenkins
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Wei Liu <sarah@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>