drm/exynos: mixer: simplify loop in vp_win_reset()

A simple while loop should do the same here.
Signed-off-by: NTobias Jakobi <tjakobi@math.uni-bielefeld.de>
Signed-off-by: NInki Dae <inki.dae@samsung.com>

drivers/gpu/drm/exynos/exynos_mixer.c

@@ -698,10 +698,10 @@ static void mixer_graph_buffer(struct mixer_context *ctx,
 static void vp_win_reset(struct mixer_context *ctx)
 {
 	struct mixer_resources *res = &ctx->mixer_res;
-	int tries = 100;
+	unsigned int tries = 100;
 
 	vp_reg_write(res, VP_SRESET, VP_SRESET_PROCESSING);
-	for (tries = 100; tries; --tries) {
+	while (tries--) {
 		/* waiting until VP_SRESET_PROCESSING is 0 */
 		if (~vp_reg_read(res, VP_SRESET) & VP_SRESET_PROCESSING)
 			break;