staging: vt6655: dead code tx path remove dma_unmap_single
staging: vt6655: dead code tx path remove dma_unmap_single

When pTDInfo->skb_dma not equal to pTDInfo->buf_dma, pTDInfo->skb_dma
equals zero.

as mentioned in comment pre-allocated buf_dma can't be unmapped
so remove dead code.

Signed-off-by: Malcolm Priestley <123fd39c698f702285d09eaebae85efdff081c95@gmail.com>
Signed-off-by: Greg Kroah-Hartman <4645f7897fd33786a2ee1264d590b3c400559d85@linuxfoundation.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs