Merge branch 'net-ll_temac-Bugfixes'

Esben Haabendal says:

====================
net: ll_temac: Bugfixes

Fix a number of bugs which have been present since the first commit.

The bugs fixed in patch 1,2 and 4 have all been observed in real systems, and
was relatively easy to reproduce given an appropriate stress setup.

Changes since v1:

- Changed error handling of of dma_map_single() in temac_start_xmit() to drop
  packet instead of returning NETDEV_TX_BUSY.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>