iwlwifi: rx: unionize the RX descriptors

Most of the fields we care about are in the same location
in both versions.

Given that, the casting to different types is not only
error-prone, but redundant as well.

Unionize the RX descriptors.

Get rid of most of the if/else and of all the castings.

This also saves quite a few code lines.

type=cleanup
ticket=none

Change-Id: Ia469f64a1f9d455bfe562195916087a7f0a4de18
Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Reviewed-on: https://git-amr-3.devtools.intel.com/gerrit/163663
automatic-review: ec ger unix iil jenkins <EC.GER.UNIX.IIL.JENKINS@INTEL.COM>
Tested-by: ec ger unix iil jenkins <EC.GER.UNIX.IIL.JENKINS@INTEL.COM>
Reviewed-by: Berg, Johannes <johannes.berg@intel.com>
x-iwlwifi-stack-dev: cd34303236f05ebc332f1bed5819b1525447d72e
4 files changed