library: raise amount by which the <stat> buffer grows

library: raise amount by which the <stat> buffer grows

We won't go as far as the merge request shown below in
increasing buffer size, but we will reduce by half the
total iterations while growing it to achieve one read.

[ and this seems in line with what was recently done ]
[ to help top under a massively parallel environment ]
[ thru 2 abreast ('4') and combined cpus ('!') modes ]

Reference(s:
https://gitlab.com/procps-ng/procps/-/merge_requests/105

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