eina_module: Drop ridiculous ERR messages from module_list_load/unload

eina_module: Drop ridiculous ERR messages from module_list_load/unload

The documentation for these functions claims that passing a NULL array
results in doing nothing - that should also include logging nothing.

EINA_SAFETY_ON_NULL_RETURN() logs an ERR message and should be reserved
for usage when NULL is not actually a valid state.

Additionally, it's entirely possible to turn off EINA_SAFETY_CHECKS, at
which point these functions would stop behaving as the documentation
says they do.  Not great.