regulator: core: Don't spew backtraces on duplicate sysfs

We don't consider a failure to add the sysfs node as a problem,
so use sysfs_create_link_nowarn() so that we don't print a
backtrace when duplicated files exist. Also, downgrade the printk
message to a debug statement so that we're quiet here. This
allows multiple drivers to request a CPU's regulator so that
CPUfreq and AVSish drivers can coexist.
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

drivers/regulator/core.c

@@ -1192,10 +1192,10 @@ static struct regulator *create_regulator(struct regulator_dev *rdev,
 		if (regulator->supply_name == NULL)
 			goto overflow_err;
 
-		err = sysfs_create_link(&rdev->dev.kobj, &dev->kobj,
+		err = sysfs_create_link_nowarn(&rdev->dev.kobj, &dev->kobj,
 					buf);
 		if (err) {
-			rdev_warn(rdev, "could not add device link %s err %d\n",
+			rdev_dbg(rdev, "could not add device link %s err %d\n",
 				  dev->kobj.name, err);
 			/* non-fatal */
 		}