misc/cgo/test: relax the threshold in test3250. Fixes build for some slow FreeBSD/NetBSD/Darwin builder.
misc/cgo/test: relax the threshold in test3250.
Fixes build for some slow FreeBSD/NetBSD/Darwin builder.

R=golang-dev
CC=golang-dev
https://codereview.appspot.com/11207043

h8liu/golang,h8liu/golang,h8liu/golang,h8liu/golang,h8liu/golang,h8liu/golang,h8liu/golang