qemu: Allow others to browse /var/lib/libvirt/qemu
    
    Commit f1f68ca33433 tried fixing running multiple domains under various
    users, but if the user can't browse the directory, it's hard for the
    qemu running under that user to create the monitor socket.
    
    The permissions need to be fixed in two places in the spec file due to
    support for both installations with and without driver modules.
    
    Creating a directory with '$(MKDIR_P) -m' shouldn't fail even on systems
    where autoconf needs to fallback to 'install-sh -d'.
    
    Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1146886
    
    Signed-off-by: Martin Kletzander <mkletzan@redhat.com>