Make lzo the default pstore compression method (bsc#1159986).
    
    Pstore has compression enabled, pstore is built-in, pstore default
    compression is deflate, deflate is modular -> pstore initialization
    fails on boot. Switch default compression to lzo which is built-in and
    the only built-in method on SLE15.
    
    Signed-off-by: Michal Suchanek <msuchanek@suse.de>