cbfs: Fix compiler error for gcc versions < 4.6

The missing braces for access to a union member
cause an error on gcc versions < 4.6.

Change-Id: I7de14a6d89219f5376f4f969adecfe8014a5a9d8
Signed-off-by: Werner Zeh <werner.zeh@siemens.com>
Reviewed-on: https://review.coreboot.org/13776
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
1 file changed