AC_SEARCH_LIBS always places the library being queried into LIBS.  We
don't want that - we were only checking whether a function is
available.  Not everything (notably not init.lxc.static) needs to
link against -lcgmanager.
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>