media: msp3400: Avoid possible out-of-bounds array accesses in msp3400c_thread()

It's possible for max1 to remain -1 if msp_read() always fail. This
variable is further used as index for accessing arrays.

Fix that by checking max1 prior to array accesses.

It seems that restart is the preferable action in case of out-of-bounds
value.

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

Fixes: 8a4b275f9c19 ("V4L/DVB (3427): audmode and rxsubchans fixes (VIDIOC_G/S_TUNER)")
Cc: [e-mail]
Signed-off-by: Ivan Abramov <[e-mail]>
Signed-off-by: Hans Verkuil <[e-mail]>

drivers/media/i2c/msp3400-kthreads.c

···
 				"carrier2 val: %5d / %s\n", val, cd[i].name);
 		}
 
+		if (max1 < 0 || max1 > 3)
+			goto restart;
 		/* program the msp3400 according to the results */
 		state->main = msp3400c_carrier_detect_main[max1].cdo;
 		switch (max1) {