Fix missing print command in a GN error case.

This mistake resulted in the error never getting reported.

Review URL: https://codereview.chromium.org/1144103004

Cr-Original-Commit-Position: refs/heads/master@{#331182}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 81d969a7fef4a51875a770e051780192a1903db6
1 file changed
tree: d860fd509a10b43d84a691c836751b0b4b5c911e
  1. tools/