warning introduced in "DMA: AT91: Get residual bytes in dma buffer"

[Arnd Bergmann]

Patch 7c407d3e "DMA: AT91: Get residual bytes in dma buffer" 
causes a build warning 

/git/arm-soc/drivers/dma/at_hdmac.c:424:13: warning: 'atc_cleanup_descriptors' defined but not used [-Wunused-function]
 static void atc_cleanup_descriptors(struct at_dma_chan *atchan)
             ^

Signed-off-by: Arnd Bergmann <arnd at arndb.de>
---

This may not be the right solution, but it should get fixed
in linux-next in some way.

Elen, please address this appropriately.

	Arnd

diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index 6db5228..09929c8 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -421,7 +421,7 @@ static void atc_complete_all(struct at_dma_chan *atchan)
  *
  * Called with atchan->lock held and bh disabled
  */
-static void atc_cleanup_descriptors(struct at_dma_chan *atchan)
+static void __maybe_unused atc_cleanup_descriptors(struct at_dma_chan *atchan)
 {
 	struct at_desc	*desc, *_desc;
 	struct at_desc	*child;