drm/exynos: fix checks for valid mixer window

Valid values for mixer window are from 0 to MIXER_WIN_NR-1 inclusive.
Arrays in structures (e.g. mixer_context.win_data) have size of
MIXER_WIN_NR so checks for wrong mixer window must be greater-equal.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Hyunhee Kim <hyunhee.kim@samsung.com>
Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

drivers/gpu/drm/exynos/exynos_drm_hdmi.c

@@ -344,7 +344,7 @@ static void drm_mixer_commit(struct device *subdrv_dev, int zpos)
 
 	DRM_DEBUG_KMS("%s\n", __FILE__);
 
-	if (win < 0 || win > MIXER_WIN_NR) {
+	if (win < 0 || win >= MIXER_WIN_NR) {
 		DRM_ERROR("mixer window[%d] is wrong\n", win);
 		return;
 	}
@@ -362,7 +362,7 @@ static void drm_mixer_disable(struct device *subdrv_dev, int zpos)
 
 	DRM_DEBUG_KMS("%s\n", __FILE__);
 
-	if (win < 0 || win > MIXER_WIN_NR) {
+	if (win < 0 || win >= MIXER_WIN_NR) {
 		DRM_ERROR("mixer window[%d] is wrong\n", win);
 		return;
 	}

drivers/gpu/drm/exynos/exynos_mixer.c

@@ -742,7 +742,7 @@ static void mixer_win_mode_set(void *ctx,
 	if (win == DEFAULT_ZPOS)
 		win = MIXER_DEFAULT_WIN;
 
-	if (win < 0 || win > MIXER_WIN_NR) {
+	if (win < 0 || win >= MIXER_WIN_NR) {
 		DRM_ERROR("mixer window[%d] is wrong\n", win);
 		return;
 	}