build_image: drop obsolete wget hack

Portage hasn't used an absolute path to /usr/bin/wget in years.
Drop this old hack since it doesn't do anything useful.

BUG=chromium:935142
TEST=precq passes

Change-Id: I7907c6b245e145a259532d2fd5f6cc5ca0a41839
Reviewed-on: https://chromium-review.googlesource.com/1485293
Commit-Ready: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Chris McDonald <cjmcdonald@chromium.org>
1 file changed