In a later commit, we will use find_if in L2. In the case of building
with E2 agent, we link e2_agent which comes with its own implementation
of find_if_arr(), which results in a name clash. Rename the OAI
implementation, as nothing uses this, anyway.
Using AssertFatal() has the drawback that it requires the definition of
an exit_function() (which is typically declared in OAI main
executables). We don't want to pull in such dependency for every
consumer. Hence, use c stdlib's assert() instead.