drm/tegra: rgb: Fix missing clk_put() in the error handling paths of tegra_dc_rgb_probe()

If clk_get_sys(..., "pll_d2_out0") fails, the clk_get_sys() call must be
undone.

Add the missing clk_put and a new 'put_pll_d_out0' label in the error
handling path, and use it.

Fixes: 0c921b6d4ba0 ("drm/tegra: dc: rgb: Allow changing PLLD rate on Tegra30+")
Signed-off-by: Christophe JAILLET <[e-mail]>
Signed-off-by: Thierry Reding <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/0182895ead[e-mail]

drivers/gpu/drm/tegra/rgb.c

···
 		if (IS_ERR(rgb->pll_d2_out0)) {
 			err = PTR_ERR(rgb->pll_d2_out0);
 			dev_err(dc->dev, "failed to get pll_d2_out0: %d\n", err);
-			goto remove;
+			goto put_pll;
 		}
 	}
 
···
 
 	return 0;
 
+put_pll:
+	clk_put(rgb->pll_d_out0);
 remove:
 	tegra_output_remove(&rgb->output);
 	return err;