dmidecode: Use the right variable for -s bios-revision/firmware-revision

It turns out that variables "offset" and "key" have the same value
for these lines of code, so there is no actual bug, nevertheless
using the right variable makes the code more obviously correct, and
less prone to introduce a bug later when adding support for new
strings.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Tested-by: Jerry Hoemann <jerry.hoemann@hpe.com>

Author: jdelvare

dmidecode.c

@@ -5386,12 +5386,12 @@ static void dmi_table_string(const struct dmi_header *h, const u8 *data, u16 ver
 	switch (key)
 	{
 		case 0x015: /* -s bios-revision */
-			if (data[key - 1] != 0xFF && data[key] != 0xFF)
-				printf("%u.%u\n", data[key - 1], data[key]);
+			if (data[offset - 1] != 0xFF && data[offset] != 0xFF)
+				printf("%u.%u\n", data[offset - 1], data[offset]);
 			break;
 		case 0x017: /* -s firmware-revision */
-			if (data[key - 1] != 0xFF && data[key] != 0xFF)
-				printf("%u.%u\n", data[key - 1], data[key]);
+			if (data[offset - 1] != 0xFF && data[offset] != 0xFF)
+				printf("%u.%u\n", data[offset - 1], data[offset]);
 			break;
 		case 0x108:
 			dmi_system_uuid(NULL, NULL, data + offset, ver);