Hi,

I was using the clang static analyzer on libqb (in preparation for using it on corosync), and found a couple of bugs:

• qb_ipcs_us_connection_acceptor() doesn't check the error return from qb_ipcs_uc_recv_and_auth(), and could end up using an uninitialized user cred structure
• more seriously, qb_rb_create_from_file() calls free on rb->shared_hdr, even though that's mmaped.

I'm not sure if either of these can happen in practice, but it seemed worth fixing.

Thanks,
J