video: ssd1307fb: add the missed regulator_disable

The driver forgets to disable the regulator in remove like what is done
in probe failure.
Add the missed call to fix it.

Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
Tested-by: Michal Vokáč <michal.vokac@ysoft.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191118114150.25724-1-hslester96@gmail.com

drivers/video/fbdev/ssd1307fb.c

@@ -791,6 +791,8 @@ static int ssd1307fb_remove(struct i2c_client *client)
 		pwm_disable(par->pwm);
 		pwm_put(par->pwm);
 	}
+	if (par->vbat_reg)
+		regulator_disable(par->vbat_reg);
 	fb_deferred_io_cleanup(info);
 	__free_pages(__va(info->fix.smem_start), get_order(info->fix.smem_len));
 	framebuffer_release(info);