firmware: dmi_scan: Fix dmi scan to handle "End of Table" structure

The dmi-sysfs should create "End of Table" entry, that is type 127. But
after adding initial SMBIOS v3 support fc430262 ("dmi: add support
for SMBIOS 3.0 64-bit entry point") the 127-0 entry is not handled any
more, as result it's not created in dmi sysfs for instance. This is
important because the size of whole DMI table must correspond to sum of
all DMI entry sizes.

So move the end-of-table check after it's handled by dmi_table.

Reviewed-by: Ard Biesheuvel <ard@linaro.org>
Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
Cc: <stable@vger.kernel.org> # v3.19
Signed-off-by: Matt Fleming <matt.fleming@intel.com>