bitfield: reformat with cargo fmt
bitfield: reformat with cargo fmt

BUG=None
TEST=cargo fmt --all -- --check

Change-Id: Ieccf6d77af27d299a08d22d9b3ee4b44bd90c5b8
Signed-off-by: Daniel Verkamp <72bc170b46ec491f7bdd4359a1c0bfed274de40c@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1370625
Reviewed-by: David Tolnay <1480464b87745a0822a0e8b7545ca981d8e7352e@chromium.org>
Reviewed-by: Dylan Reid <c791bfe44996c1eed9c7149a0c5f12a86d58eb85@chromium.org>

google/crosvm,google/crosvm,google/crosvm,google/crosvm