Factor out the code that cleans up a number of connected TX descriptors,
as we will need it to properly roll back a failed _xmit() call.
There are subtle differences between cleaning up a successfully sent
chain (unknown number of involved descriptors, total data size needed)
and a chain that was about to set up (number of descriptors known), so
cater for those variations with some extra parameters.
Signed-off-by: NAndre Przywara <andre.przywara@arm.com>
Reviewed-by: NRadhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>