If the user sets any preinit options in .config, the wrong path may get
applied due to wrong default value in image-config.in and due to Makefile
writing also the unchanged options into 00_preinit.conf

Modify the default path in image-config.in to match the current default
path set by r47080. Also modify the fall-back default in Makefile.

Signed-off-by: Hannu Nyman <hannu.nyman@iki.fi>

SVN-Revision: 47590