sparc: implement ->mapping_error

DMA_ERROR_CODE is going to go away, so don't rely on it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: David S. Miller <davem@davemloft.net>

arch/sparc/include/asm/dma-mapping.h

@@ -5,8 +5,6 @@
 #include <linux/mm.h>
 #include <linux/dma-debug.h>
 
-#define DMA_ERROR_CODE	(~(dma_addr_t)0x0)
-
 #define HAVE_ARCH_DMA_SUPPORTED 1
 int dma_supported(struct device *dev, u64 mask);