Fix incorrect wording in README

This fixes a minor editing problem in the file.

BUG=none
TEST=none

Change-Id: Ia70905c198af87841a75dfa154e9c715baf48b1c
Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/274052
Reviewed-by: Mike Frysinger <vapier@chromium.org>
1 file changed