media: pt1: fix strncmp() size warning

As warned by smatch:
	drivers/media/pci/pt1/pt1.c:213 config_demod() error: strncmp() '"tc90522sat"' too small (11 vs 20)

Use the same strncmp() syntax as pt1_init_frontends() does.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/media/pci/pt1/pt1.c

@@ -210,7 +210,8 @@ static int config_demod(struct i2c_client *cl, enum pt1_fe_clk clk)
 		return ret;
 	usleep_range(30000, 50000);
 
-	is_sat = !strncmp(cl->name, TC90522_I2C_DEV_SAT, I2C_NAME_SIZE);
+	is_sat = !strncmp(cl->name, TC90522_I2C_DEV_SAT,
+			  strlen(TC90522_I2C_DEV_SAT));
 	if (is_sat) {
 		struct i2c_msg msg[2];
 		u8 wbuf, rbuf;