sync/atomic: delete workaround Load seems to work on arm now.
sync/atomic: delete workaround
Load seems to work on arm now.

R=dsymonds
CC=golang-dev
http://codereview.appspot.com/4795042
abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go