fs_template._ensure_dirs: handle EEXIST (529120)

There was a race inside fs_template._ensure_dirs which could cause it to
raise EEXIST if a concurrent process created the directory after
os.path.exists returned False. Fix it by using the util.ensure_dirs
function, which already handles EEXIST.

(Cherry picked from 9f6967dbc38ea55c0de5fbf5ad663ca676c54743)

Change-Id: Ic681cebf6b700916316a364096e9bd4d82238de1
X-Gentoo-Bug: 529120
X-Gentoo-Bug-URL: https://bugs.gentoo.org/show_bug.cgi?id=529120
Acked-by: Alexander Berntsen <bernalex@gentoo.org>
Reviewed-on: https://chromium-review.googlesource.com/271333
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Tested-by: Bertrand Simonnet <bsimonnet@chromium.org>
1 file changed