powerpc: Simplify test in __dma_sync()

This simplification helps the compiler. We now have only one test
instead of two, so it reduces the number of branches.
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: NScott Wood <oss@buserror.net>

arch/powerpc/mm/dma-noncoherent.c

@@ -327,7 +327,7 @@ void __dma_sync(void *vaddr, size_t size, int direction)
 		 * invalidate only when cache-line aligned otherwise there is
 		 * the potential for discarding uncommitted data from the cache
 		 */
-		if ((start & (L1_CACHE_BYTES - 1)) || (size & (L1_CACHE_BYTES - 1)))
+		if ((start | end) & (L1_CACHE_BYTES - 1))
 			flush_dcache_range(start, end);
 		else
 			invalidate_dcache_range(start, end);