firmware: dmi_scan: Fix UUID endianness for SMBIOS >= 2.6

commit ff4319dc upstream.

The dmi_ver wasn't updated correctly before the dmi_decode method run
to save the uuid.

That resulted in "dmidecode -s system-uuid" and
/sys/class/dmi/id/product_uuid disagreeing. The latter was buggy and
this fixes it.
Reported-by: Federico Simoncelli <fsimonce@redhat.com>
Fixes: 9f9c9cbb ("drivers/firmware/dmi_scan.c: fetch dmi version from SMBIOS if it exists")
Fixes: 79bae42d ("dmi_scan: refactor dmi_scan_machine(), {smbios,dmi}_present()")
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Jean Delvare <jdelvare@suse.de>
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

drivers/firmware/dmi_scan.c

@@ -493,6 +493,7 @@ static int __init dmi_present(const u8 *buf)
 			dmi_ver = smbios_ver;
 		else
 			dmi_ver = (buf[14] & 0xF0) << 4 | (buf[14] & 0x0F);
+		dmi_ver <<= 8;
 		dmi_num = (buf[13] << 8) | buf[12];
 		dmi_len = (buf[7] << 8) | buf[6];
 		dmi_base = (buf[11] << 24) | (buf[10] << 16) |
@@ -501,10 +502,10 @@ static int __init dmi_present(const u8 *buf)
 		if (dmi_walk_early(dmi_decode) == 0) {
 			if (smbios_ver) {
 				pr_info("SMBIOS %d.%d present.\n",
-				       dmi_ver >> 8, dmi_ver & 0xFF);
+					dmi_ver >> 16, (dmi_ver >> 8) & 0xFF);
 			} else {
 				pr_info("Legacy DMI %d.%d present.\n",
-				       dmi_ver >> 8, dmi_ver & 0xFF);
+					dmi_ver >> 16, (dmi_ver >> 8) & 0xFF);
 			}
 			dmi_format_ids(dmi_ids_string, sizeof(dmi_ids_string));
 			printk(KERN_DEBUG "DMI: %s\n", dmi_ids_string);