Patch from Kevin Hilman
Previous locking changes to dmabounce incorrectly return non-NULL even
when buffer not found.  Fix it up.
Signed-off-by: Kevin Hilman <khilman@mvista.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
 static inline struct safe_buffer *
 find_safe_buffer(struct dmabounce_device_info *device_info, dma_addr_t safe_dma_addr)
 {
-       struct safe_buffer *b = NULL;
+       struct safe_buffer *b, *rb = NULL;
        unsigned long flags;
 
        read_lock_irqsave(&device_info->lock, flags);
 
        list_for_each_entry(b, &device_info->safe_buffers, node)
-               if (b->safe_dma_addr == safe_dma_addr)
+               if (b->safe_dma_addr == safe_dma_addr) {
+                       rb = b;
                        break;
+               }
 
        read_unlock_irqrestore(&device_info->lock, flags);
-       return b;
+       return rb;
 }
 
 static inline void