dmaengine: print more meaningful error message

error log for dma_channel_table_init() failure pointed a mere
"initialization failure", which is not very helpful message, so print
additional details like function name and error code.
Signed-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/dmaengine.c

@@ -206,7 +206,7 @@ static int __init dma_channel_table_init(void)
 	}
 
 	if (err) {
-		pr_err("initialization failure\n");
+		pr_err("dmaengine dma_channel_table_init failure: %d\n", err);
 		for_each_dma_cap_mask(cap, dma_cap_mask_all)
 			free_percpu(channel_table[cap]);
 	}