Since no skb will be mapped for RX and TX at the same time we can
simply shortcut the check for SKBDESC_DMA_MAPPED_TX.
Signed-off-by: NHelmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>