media: dvb: mb86a20s: get rid of a clang-15 warning

When building with clang-15: this warning is produced:

	../drivers/media/dvb-frontends/mb86a20s.c:1572:6: error: variable 'active_layers' set but not used [-Werror,-Wunused-but-set-variable]
	        int active_layers = 0, pre_ber_layers = 0, post_ber_layers = 0;
	            ^
	1 error generated.

Link: https://lore.kernel.org/linux-media/20230628130339.206261-1-mchehab@kernel.org
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

drivers/media/dvb-frontends/mb86a20s.c

@@ -1569,7 +1569,7 @@ static int mb86a20s_get_stats(struct dvb_frontend *fe, int status_nr)
 	u32 t_post_bit_error = 0, t_post_bit_count = 0;
 	u32 block_error = 0, block_count = 0;
 	u32 t_block_error = 0, t_block_count = 0;
-	int active_layers = 0, pre_ber_layers = 0, post_ber_layers = 0;
+	int pre_ber_layers = 0, post_ber_layers = 0;
 	int per_layers = 0;
 
 	dev_dbg(&state->i2c->dev, "%s called.\n", __func__);
@@ -1589,9 +1589,6 @@ static int mb86a20s_get_stats(struct dvb_frontend *fe, int status_nr)
 
 	for (layer = 0; layer < NUM_LAYERS; layer++) {
 		if (c->isdbt_layer_enabled & (1 << layer)) {
-			/* Layer is active and has rc segments */
-			active_layers++;
-
 			/* Handle BER before vterbi */
 			rc = mb86a20s_get_pre_ber(fe, layer,
 						  &bit_error, &bit_count);