selinux: Begin and end the transaction on the same nesting level
    
    Transaction should be started and commited on the same code nesting or
    abstraction level. Also, transactions are really costly with libselinux
    and splitting them from initialization will make init function reusable
    by read-only libsemanage functions.
    
    Reviewed-by: Michal Židek <mzidek@redhat.com>
    (cherry picked from commit 748b38a7991d78cbf4726f2a14ace5e926629a54)