abis_nm: Simplify param passing to abis_nm_rx_get_attr_resp()

There's no real need to retrieve the trx before passing it to the
function, we can do that in the function itself and hence also simplify
the function itself.

Related: OS#4870
Change-Id: I7181510c5021ff2712c09ebc6ec8b13fdd8e8dc2
1 file changed