i2c: Improve deprecation warnings

When warning on the use of deprecated i2c_driver methods
attach_adapter and detach_adapter, mention the name of the driver
which needs to be updated.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 70c30e6..9a58994 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -797,7 +797,8 @@
 
 	/* Let legacy drivers scan this bus for matching devices */
 	if (driver->attach_adapter) {
-		dev_warn(&adap->dev, "attach_adapter method is deprecated\n");
+		dev_warn(&adap->dev, "%s: attach_adapter method is deprecated\n",
+			 driver->driver.name);
 		dev_warn(&adap->dev, "Please use another way to instantiate "
 			 "your i2c_client\n");
 		/* We ignore the return code; if it fails, too bad */
@@ -984,7 +985,8 @@
 
 	if (!driver->detach_adapter)
 		return 0;
-	dev_warn(&adapter->dev, "detach_adapter method is deprecated\n");
+	dev_warn(&adapter->dev, "%s: detach_adapter method is deprecated\n",
+		 driver->driver.name);
 	res = driver->detach_adapter(adapter);
 	if (res)
 		dev_err(&adapter->dev, "detach_adapter failed (%d) "