fec: fix FEC driver packet transmission breakage

Commit f0b3fbea ("FEC Buffer rework")
breaks transmission of packets where the skb data buffer is not memory
aligned according to FEC_ALIGNMENT. It incorrectly passes to
dma_sync_single() the buffer address directly from the skb, instead of
the address calculated for use (which may be the skb address or one of
the bounce buffers).

It seems there is no use converting the cpu address of the buffer to
a physical either, since dma_map_single() expects the cpu address and
will return the dma address to use in the descriptor. So remove the use
of __pa() on the buffer address as well.

This patch is against 2.6.30-rc5. This breakage is a regression over
2.6.30, which does not have this problem.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: David S. Miller <davem@davemloft.net>