[PATCH] dma: remove bad_dma_ops to fix build fail

[Sudip Mukherjee <sudipm.mukherjee@gmail.com>]

m32r allmodconfig is failng with errors like:
ERROR: "bad_dma_ops" [sound/soc/bcm/snd-soc-cygnus.ko] undefined!

On checking the code it turns out that struct bad_dma_ops has been
declared as extern but no one has actually defined struct bad_dma_ops.
Lets remove that and return NULL from get_dma_ops() if HAS_DMA is not
defined.

Signed-off-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>
---

This patch has been build tested with m32r allmodconfig,
x86_64 allmodconfig and i386 allmodconfig.

 include/linux/dma-mapping.h | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 71c1b21..583795a 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -113,10 +113,9 @@ int dma_mmap_from_coherent(struct device *dev, struct vm_area_struct *vma,
  * dma dependent code.  Code that depends on the dma-mapping
  * API needs to set 'depends on HAS_DMA' in its Kconfig
  */
-extern struct dma_map_ops bad_dma_ops;
 static inline struct dma_map_ops *get_dma_ops(struct device *dev)
 {
-	return &bad_dma_ops;
+	return NULL;
 }
 #endif
 
-- 
1.9.1