media: pulse8-cec: print time using time64_t

The firmware timestamp is an unsigned 32-bit value, but we copy it into
a signed 32-bit variable, so we can theoretically get an overflow in
the calculation when the timestamp is between 2038 and 2106.

This changes the temporary variable to time64_t and changes the deprecated
time_to_tm() over to time64_to_tm() accordingly.

There is still an overflow in y2106, but that is a limitation of the
firmware interface, not a kernel problem.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/usb/pulse8-cec/pulse8-cec.c

@@ -329,7 +329,7 @@ static int pulse8_setup(struct pulse8 *pulse8, struct serio *serio,
 	u8 cmd[2];
 	int err;
 	struct tm tm;
-	time_t date;
+	time64_t date;
 
 	pulse8->vers = 0;
 
@@ -349,7 +349,7 @@ static int pulse8_setup(struct pulse8 *pulse8, struct serio *serio,
 	if (err)
 		return err;
 	date = (data[0] << 24) | (data[1] << 16) | (data[2] << 8) | data[3];
-	time_to_tm(date, 0, &tm);
+	time64_to_tm(date, 0, &tm);
 	dev_info(pulse8->dev, "Firmware build date %04ld.%02d.%02d %02d:%02d:%02d\n",
 		 tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
 		 tm.tm_hour, tm.tm_min, tm.tm_sec);