media: vivid: remove redundant assignment to variable checksum

Variable checksum is assigned a value that is never read, it is assigned
a new value in a following for-loop. The assignment is redundant and can
be removed.

Cleans up clang scan build warning:
drivers/media/test-drivers/vivid/vivid-vbi-gen.c:197:2: warning: Value
stored to 'checksum' is never read [deadcode.DeadStores]
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

drivers/media/test-drivers/vivid/vivid-vbi-gen.c

@@ -194,7 +194,6 @@ static void vivid_vbi_gen_set_time_of_day(u8 *packet)
 	for (checksum = i = 0; i <= 8; i++)
 		checksum += packet[i] & 0x7f;
 	packet[9] = calc_parity(0x100 - checksum);
-	checksum = 0;
 	packet[10] = calc_parity(0x07);
 	packet[11] = calc_parity(0x04);
 	if (sys_tz.tz_minuteswest >= 0)