top: refactor 3 routines ahead of the separate threads

top: refactor 3 routines ahead of the separate threads

This commit sets the stage for turning three functions
into code that can support a separate thread to update
their respective data while working in the background.

It involved relocating 1 function, renaming 2 routines
and adding parameters plus return addresses to each of
three functions. Those latter changes will be required
when issuing 'pthread_create' calls in the next patch.

The final step was organizing this code into what will
become the infinite do-while loop supporting a thread.

Signed-off-by: Jim Warner <james.warner@comcast.net>