Fix cscope target

At the moment, the cscope target fails to build:

    $ make cscope
    Making cscopelist in libcompat
    Making cscopelist in libutils
    Making cscopelist in libpromises
    Making cscopelist in cf-agent
    Making cscopelist in cf-execd
    Making cscopelist in cf-gendoc
    Making cscopelist in cf-key
    Making cscopelist in cf-monitord
    make[1]: *** No rule to make target `cf-monitord-enterpsise-stubs.h', needed by `cscopelist-am'.  Stop.
    make: *** [cscopelist-recursive] Error 1