fbdev: ssd1307fb: Print the PWM's label instead of its number

struct pwm_device::pwm is a write-only variable in the pwm core and used
nowhere apart from this and another dev_dbg. So it isn't useful to
identify the used PWM. Emit the PWM's label instead in the debug
message.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: Helge Deller <deller@gmx.de>

drivers/video/fbdev/ssd1307fb.c

@@ -399,8 +399,8 @@ static int ssd1307fb_init(struct ssd1307fb_par *par)
 		/* Enable the PWM */
 		pwm_enable(par->pwm);
 
-		dev_dbg(&par->client->dev, "Using PWM%d with a %lluns period.\n",
-			par->pwm->pwm, pwm_get_period(par->pwm));
+		dev_dbg(&par->client->dev, "Using PWM %s with a %lluns period.\n",
+			par->pwm->label, pwm_get_period(par->pwm));
 	}
 
 	/* Set initial contrast */