Build file templates would be looked up like this if the user gave us
an additional directory to look for configuration files and build file
templates:

    $OPENSSL_LOCAL_CONFIG_DIR/$OSTYPE-Makefile.tmpl
    $SOURCEDIR/Configurations/$OSTYPE-Makefile.tmpl
    $OPENSSL_LOCAL_CONFIG_DIR/Makefile.tmpl
    $SOURCEDIR/Configurations/Makefile.tmpl

So for example, if the user created his own Makefile.tmpl and tried to
use it with a unixly config, it would never be user because we have a
unix-Makefile.tmpl in our Configurations directory.  This is clearly
wrong, and this change makes it look in this order instead:

    $OPENSSL_LOCAL_CONFIG_DIR/$OSTYPE-Makefile.tmpl
    $OPENSSL_LOCAL_CONFIG_DIR/Makefile.tmpl
    $SOURCEDIR/Configurations/$OSTYPE-Makefile.tmpl
    $SOURCEDIR/Configurations/Makefile.tmpl
Reviewed-by: NRich Salz <rsalz@openssl.org>