x86: unused variable in dma_alloc_coherent_gfp_flags()

Fixed a warning caused by a badly placed ifdef.
Signed-off-by: NSteven Noonan <steven@uplinklabs.net>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

include/asm-x86/dma-mapping.h

@@ -253,9 +253,9 @@ static inline unsigned long dma_alloc_coherent_mask(struct device *dev,
 
 static inline gfp_t dma_alloc_coherent_gfp_flags(struct device *dev, gfp_t gfp)
 {
+#ifdef CONFIG_X86_64
 	unsigned long dma_mask = dma_alloc_coherent_mask(dev, gfp);
 
-#ifdef CONFIG_X86_64
 	if (dma_mask <= DMA_32BIT_MASK && !(gfp & GFP_DMA))
 		gfp |= GFP_DMA32;
 #endif