LU-2675 llapi: find_param cleanup part II

LU-2675 llapi: find_param cleanup part II

Add fp_ prefixes to the remaining members of struct find_param. Also
add underscores between words in several member names:
  obduuid -> fp_obd_uuid
  stripesize_units -> fp_stripe_size_units
  ...

Signed-off-by: John L. Hammond <john.hammond@intel.com>
Change-Id: Iaa62a6b44e2929f3925525a97fec0434243dec1b
Reviewed-on: http://review.whamcloud.com/12851
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>