ARM: 8419/1: dma-mapping: harmonize definition of DMA_ERROR_CODE

All architectures except arm that define DMA_ERROR_CODE are casting it
to (dma_addr_t) - as it is always compared to dma_addr_t in arm as well
this could be harmonized.

Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>