media: cx24120: Add retval check for cx24120_message_send()

[ Upstream commit 96002c0 ]

If cx24120_message_send() returns error, we should keep local struct
unchanged.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 5afc9a2 ("[media] Add support for TechniSat Skystar S2")
Signed-off-by: Daniil Dulov <d.dulov@aladdin.ru>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/media/dvb-frontends/cx24120.c

@@ -973,7 +973,9 @@ static void cx24120_set_clock_ratios(struct dvb_frontend *fe)
 	cmd.arg[8] = (clock_ratios_table[idx].rate >> 8) & 0xff;
 	cmd.arg[9] = (clock_ratios_table[idx].rate >> 0) & 0xff;
 
-	cx24120_message_send(state, &cmd);
+	ret = cx24120_message_send(state, &cmd);
+	if (ret != 0)
+		return;
 
 	/* Calculate ber window rates for stat work */
 	cx24120_calculate_ber_window(state, clock_ratios_table[idx].rate);