dma: dmagengine: fix function names in comments

Trivial fix for function name mismatches I stumbled over.

Signed-off-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index 5932ab1..0947ff6 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -504,7 +504,7 @@
 }
 
 /**
- * dma_request_channel - try to get specific channel exclusively
+ * dma_request_slave_channel - try to get specific channel exclusively
  * @chan: target channel
  */
 struct dma_chan *dma_get_slave_channel(struct dma_chan *chan)
@@ -530,7 +530,7 @@
 EXPORT_SYMBOL_GPL(dma_get_slave_channel);
 
 /**
- * dma_request_channel - try to allocate an exclusive channel
+ * __dma_request_channel - try to allocate an exclusive channel
  * @mask: capabilities that the channel must satisfy
  * @fn: optional callback to disposition available channels
  * @fn_param: opaque parameter to pass to dma_filter_fn