drm/exynos: gsc: minor fix for loop iteration in gsc_runtime_resume

Do not forget to call clk_disable_unprepare() on the first element of
ctx->clocks array.

Found by Linux Verification Center (linuxtesting.org).

Fixes: 8b7d3ec8 ("drm/exynos: gsc: Convert driver to IPP v2 core API")
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

drivers/gpu/drm/exynos/exynos_drm_gsc.c

@@ -1342,7 +1342,7 @@ static int __maybe_unused gsc_runtime_resume(struct device *dev)
 	for (i = 0; i < ctx->num_clocks; i++) {
 		ret = clk_prepare_enable(ctx->clocks[i]);
 		if (ret) {
-			while (--i > 0)
+			while (--i >= 0)
 				clk_disable_unprepare(ctx->clocks[i]);
 			return ret;
 		}