gosrc: add missing context parameters to print.go

Support for the context package was added in baa18d8, but the
gosrc/print.go debug utility was never updated, and since it has the
ignore build tag go test etc. didn't catch this.

This will not affect godoc.org operation; it's just a debug utility for
developers; it was helpful for me in examining #576.

Change-Id: Ie48ede8b1a54289d5dd848c4ca7867fd9ca38a02
GitHub-Last-Rev: ad319e617b08ec6edfbec6957c1ee8d4fac85d81
GitHub-Pull-Request: golang/gddo#577
Reviewed-on: https://go-review.googlesource.com/132655
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
1 file changed