When bringing down the TX rings we flush the rings but forget to
reclaimed the flushed packets. This lead to a memory leak since we
do not free the dma mapped buffers. This also leads to tx control
block corruption when bringing down the interface for power
management.
Fixes: 490cb412007d ("net: bcmasp: Add support for ASP2.0 Ethernet controller")
Signed-off-by: Justin Chen <justin.chen@xxxxxxxxxxxx>