smbios: Correct error handling when writing tables

Since write_smbios_table() returns an address, we cannot use it to
return and error number. Also, failing on sysinfo_detect() breaks
existing boards, e.g. chromebook_link

Correct this by logging and swallowing the error.

Signed-off-by: Simon Glass <sjg@chromium.org>
Fixes: a5a57562 ("lib: smbios: Detect system properties via...")