misc/dist/darwin: add execute bit to preinstall

Fixes #5258.

R=golang-dev, iant, minux.ma
CC=golang-dev
https://golang.org/cl/8682043

diff --git a/misc/dist/darwin/scripts/preinstall b/misc/dist/darwin/scripts/preinstall
old mode 100644 (file)
new mode 100755 (executable)