fbdev: da8xx-fb: go to proper label on error handling paths in probe

fb_probe() can successfully allocate a new frame buffer, but then fail
to perform some operations with regulator. In these cases fb_probe()
goes to label err_pm_runtime_disable where the frame buffer is not
released. The patch makes fb_probe() to go to label err_release_fb on
corresponding error handling paths.

Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Evgeny Novikov <novikov@ispras.ru>
Cc: Sekhar Nori <nsekhar@ti.com>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200702160540.24546-1-novikov@ispras.ru

drivers/video/fbdev/da8xx-fb.c

@@ -1402,14 +1402,14 @@ static int fb_probe(struct platform_device *device)
 	if (IS_ERR(par->lcd_supply)) {
 		if (PTR_ERR(par->lcd_supply) == -EPROBE_DEFER) {
 			ret = -EPROBE_DEFER;
-			goto err_pm_runtime_disable;
+			goto err_release_fb;
 		}
 
 		par->lcd_supply = NULL;
 	} else {
 		ret = regulator_enable(par->lcd_supply);
 		if (ret)
-			goto err_pm_runtime_disable;
+			goto err_release_fb;
 	}
 
 	fb_videomode_to_var(&da8xx_fb_var, lcdc_info);