mac80211: refactor rc_no_data_or_no_ack_use_min function

Use newly introduced helper function ieee80211_is_tx_data to check if
frame is a data frame. Takes into account that hardware encapsulation
can be enabled for a frame and therefore no ieee80211 header is present.

Signed-off-by: Philipp Borgers <borgers@mi.fu-berlin.de>
Link: https://lore.kernel.org/r/20210519122019.92359-4-borgers@mi.fu-berlin.de


Signed-off-by: Johannes Berg <johannes.berg@intel.com>