[PATCH] Use valid_dma_direction() in include/asm-i386/dma-mapping.h

Now that the generic DMA code has a function to decide if a given DMA
mapping is valid use it.  This will catch cases where direction is not any
of the defined enum values but some random number outside the valid range.
The current implementation will only catch the defined but invalid case
DMA_NONE.

Signed-off-by: Rolf Eike Beer <eike-kernel@sf-tec.de>
Acked-by: Muli Ben-Yehuda <muli@il.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>