drm/nouveau/kms/nv04-nv4x: Use match_string() helper to simplify the code

match_string() returns the array index of a matching string.
Use it instead of the open-coded implementation.
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/dispnv04/tvnv17.c

@@ -644,16 +644,13 @@ static int nv17_tv_create_resources(struct drm_encoder *encoder,
 	int i;
 
 	if (nouveau_tv_norm) {
-		for (i = 0; i < num_tv_norms; i++) {
-			if (!strcmp(nv17_tv_norm_names[i], nouveau_tv_norm)) {
-				tv_enc->tv_norm = i;
-				break;
-			}
-		}
-
-		if (i == num_tv_norms)
+		i = match_string(nv17_tv_norm_names, num_tv_norms,
+				 nouveau_tv_norm);
+		if (i < 0)
 			NV_WARN(drm, "Invalid TV norm setting \"%s\"\n",
 				nouveau_tv_norm);
+		else
+			tv_enc->tv_norm = i;
 	}
 
 	drm_mode_create_tv_properties(dev, num_tv_norms, nv17_tv_norm_names);