The next patch reworks how the IPA packet status structure is
interpreted.  This patch does some preparatory work, to make it
easier to see the effect of that change:
  - Change a few functions that access fields in a IPA packet status
    structure to store field values in local variables with names
    related to the field.
  - Pass a void pointer rather than an (equivalent) status pointer
    to two functions called by ipa_endpoint_status_parse().
  - Use "rule" rather than "val" as the name of a variable that
    holds a routing rule ID.
  - Consistently use "IPA packet status" rather than "status
    element" when referring to this data structure.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>