Generic dma-coherent: fix DMA_MEMORY_EXCLUSIVE

Don't rewrite successfull allocation return values
in case the memory was marked with DMA_MEMORY_EXCLUSIVE.

Signed-off-by: Dmitry Baryshkov <[e-mail]>
Cc: Jesse Barnes <[e-mail]>
Signed-off-by: Ingo Molnar <[e-mail]>

kernel/dma-coherent.c

···
 			*dma_handle = mem->device_base + (page << PAGE_SHIFT);
 			*ret = mem->virt_base + (page << PAGE_SHIFT);
 			memset(*ret, 0, size);
-		}
-		if (mem->flags & DMA_MEMORY_EXCLUSIVE)
+		} else if (mem->flags & DMA_MEMORY_EXCLUSIVE)
 			*ret = NULL;
 	}
 	return (mem != NULL);