Fix build system

For example: ./build_oai -I -w USRP -> does run the CMAKE and build at least params_libconfig and coding.Rel15.txt

It should stop after the end of the 2nd section 2. Setting the OAI PATHS ...

Note that in the VM builds we are doing something like ./build_oai -I -w USRP --eNB --> There it should NOT stop.