top: still more tidying up after <pids> implementation

top: still more tidying up after <pids> implementation

A patch containing the following miscellaneous tweaks:

. remove a function that handled former library errors
[ that function should have gone bye-bye with 3.3.11 ]
[ when those 'wchan' provisions were much simplified ]

. make clearer a distinction between 'new' and 'reset'
[ use PROCPS_PIDS_noop when procps_pids_new() called ]
[ since at that point we are only establishing depth ]

Reference(s):
http://www.freelists.org/post/procps/newlib-for-pgrep,1

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