dmaengine: Add a comment on why it's okay when kasprintf() fails

Add a comment in dma_request_chan() to clarify kasprintf() missing return
value check and it is correct functionality.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20250205145757.889247-4-andriy.shevchenko@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Author: andy-shev

drivers/dma/dmaengine.c

@@ -854,8 +854,8 @@ struct dma_chan *dma_request_chan(struct device *dev, const char *name)
 
 found:
 #ifdef CONFIG_DEBUG_FS
-	chan->dbg_client_name = kasprintf(GFP_KERNEL, "%s:%s", dev_name(dev),
-					  name);
+	chan->dbg_client_name = kasprintf(GFP_KERNEL, "%s:%s", dev_name(dev), name);
+	/* No functional issue if it fails, users are supposed to test before use */
 #endif
 
 	chan->name = kasprintf(GFP_KERNEL, "dma:%s", name);