Fix a typo in the documentation of "gn help data".

Review URL: https://codereview.chromium.org/1907643002

Cr-Original-Commit-Position: refs/heads/master@{#388621}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 9926d94c764e2c557208ffb80e8b58f8506dff45
1 file changed
tree: c927037fb81ed09d72234caa978e90d26c2ce37f
  1. tools/