USB: replace dma_sync_single and dma_sync_sg with dma_sync_single_for_cpu and dma_sync_sg_for_cpu

This replaces dma_sync_single() and dma_sync_sg() with
dma_sync_single_for_cpu() and dma_sync_sg_for_cpu() respectively
because they is an obsolete API; include/linux/dma-mapping.h says:

/* Backwards compat, remove in 2.7.x */
#define dma_sync_single		dma_sync_single_for_cpu
#define dma_sync_sg		dma_sync_sg_for_cpu

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>