CHROMIUM: virtwl: fix incorrect list_for_each_entry_safe usage

TEST=None
BUG=None

Change-Id: Id5e939310dc4a3b3b4bccfc30e606e961c08f0e3
Signed-off-by: Zach Reizner <zachr@google.com>
Reviewed-on: https://chromium-review.googlesource.com/742145
Commit-Ready: Zach Reizner <zachr@chromium.org>
Tested-by: Zach Reizner <zachr@chromium.org>
Reviewed-by: Stephen Barber <smbarber@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/780814
Commit-Ready: Dylan Reid <dgreid@chromium.org>
Tested-by: Dylan Reid <dgreid@chromium.org>
Reviewed-by: Zach Reizner <zachr@chromium.org>