fbdev: da8xx-fb: add missing regulator_disable() in fb_probe

The error handling code in fb_probe misses regulator_disable if
regulator_enable is called successfully. The previous commit only
adds regulator_disable in the .remove(), forgetting the error
handling code in the .probe.

Fix this by adding a new error label to call regulator_disable.

Fixes: 611097d5daea("fbdev: da8xx: add support for a regulator")
Signed-off-by: Dongliang Mu <[e-mail]>
Signed-off-by: Helge Deller <[e-mail]>

drivers/video/fbdev/da8xx-fb.c

···
 		dev_err(&device->dev,
 			"GLCD: kmalloc for frame buffer failed\n");
 		ret = -EINVAL;
-		goto err_release_fb;
+		goto err_disable_reg;
 	}
 
 	da8xx_fb_info->screen_base = (char __iomem *) par->vram_virt;
···
 
 	ret = fb_alloc_cmap(&da8xx_fb_info->cmap, PALETTE_SIZE, 0);
 	if (ret)
-		goto err_release_fb;
+		goto err_disable_reg;
 	da8xx_fb_info->cmap.len = par->palette_sz;
 
 	/* initialize var_screeninfo */
···
 err_dealloc_cmap:
 	fb_dealloc_cmap(&da8xx_fb_info->cmap);
 
+err_disable_reg:
+	if (par->lcd_supply)
+		regulator_disable(par->lcd_supply);
 err_release_fb:
 	framebuffer_release(da8xx_fb_info);