firmware: dmi: Use the proper accessor for the version field

The byte at offset 6 represents length. Don't take it and drop it
immediately by using proper accessor, i.e. get_unaligned_be24().

[JD: Change the subject to something less frightening]
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jean Delvare <jdelvare@suse.de>

drivers/firmware/dmi_scan.c

@@ -630,7 +630,7 @@ static int __init dmi_smbios3_present(const u8 *buf)
 {
 	if (memcmp(buf, "_SM3_", 5) == 0 &&
 	    buf[6] < 32 && dmi_checksum(buf, buf[6])) {
-		dmi_ver = get_unaligned_be32(buf + 6) & 0xFFFFFF;
+		dmi_ver = get_unaligned_be24(buf + 7);
 		dmi_num = 0;			/* No longer specified */
 		dmi_len = get_unaligned_le32(buf + 12);
 		dmi_base = get_unaligned_le64(buf + 16);