Add documentation and more verbose variable names to minstrel's
multi-rate-retry setup within function minstrel_get_rate() to
increase the readability of the algorithm.
Acked-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NThomas Huehn <thomas@net.t-labs.tu-berlin.de>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>