Most of the time, the return value tells us nothing useful, as we've
already decided that we're perfectly willing to live with string
truncation. Hopefully this keeps Coverity from whining that those
routines could return an error code (NARRATOR: They don't) and thus that
we're ignoring the possibility of failure (as indicated, we've already
decided that we can live with string truncation, so truncation is *NOT*
a failure).
The distinction between the different kinds of capture utility
may not warrant a special subfolfer for each, and sometimes the
distinction is not be clear or some functions could stradle
multiple "categories" (like capture_ifinfo.[ch]).
Simplify by having only a generic 'capture' subfolder. The
separate CMake libraries are kept as a way to reuse object code
efficiently.