doc: tweak Solaris wording
doc: tweak Solaris wording

Suggested in comments on CL 85740043.

LGTM=aram
R=golang-codereviews, aram
CC=dave, golang-codereviews, r
https://codereview.appspot.com/85990044

wesolows/golang-old,wesolows/golang-old,wesolows/golang,firebitsbr/golang-old,wesolows/golang-old,wesolows/golang,firebitsbr/golang-old,firebitsbr/golang-old,firebitsbr/golang-old,wesolows/golang,firebitsbr/golang-old,wesolows/golang-old,wesolows/golang,wesolows/golang-old,firebitsbr/golang-old,wesolows/golang,wesolows/golang,wesolows/golang,firebitsbr/golang-old,wesolows/golang-old,wesolows/golang-old,firebitsbr/golang-old