Fix the Skylark specification
Fix the Skylark specification

Return statements can exist without an expression.

PiperOrigin-RevId: 184291539

twitter-forks/bazel,dropbox/bazel,akira-baruah/bazel,ulfjack/bazel,perezd/bazel,safarmer/bazel,twitter-forks/bazel,ulfjack/bazel,dslomov/bazel,bazelbuild/bazel,ulfjack/bazel,perezd/bazel,werkt/bazel,akira-baruah/bazel,katre/bazel,dslomov/bazel-windows,dropbox/bazel,ulfjack/bazel,dslomov/bazel-windows,meteorcloudy/bazel,twitter-forks/bazel,akira-baruah/bazel,werkt/bazel,bazelbuild/bazel,ButterflyNetwork/bazel,aehlig/bazel,katre/bazel,dropbox/bazel,davidzchen/bazel,katre/bazel,werkt/bazel,akira-baruah/bazel,aehlig/bazel,twitter-forks/bazel,perezd/bazel,dslomov/bazel-windows,dslomov/bazel,akira-baruah/bazel,safarmer/bazel,cushon/bazel,davidzchen/bazel,cushon/bazel,meteorcloudy/bazel,meteorcloudy/bazel,aehlig/bazel,dropbox/bazel,ButterflyNetwork/bazel,dslomov/bazel,katre/bazel,meteorcloudy/bazel,meteorcloudy/bazel,werkt/bazel,ButterflyNetwork/bazel,davidzchen/bazel,dslomov/bazel-windows,dslomov/bazel,werkt/bazel,bazelbuild/bazel,safarmer/bazel,dropbox/bazel,bazelbuild/bazel,dslomov/bazel-windows,aehlig/bazel,dslomov/bazel,ulfjack/bazel,meteorcloudy/bazel,dslomov/bazel-windows,twitter-forks/bazel,davidzchen/bazel,werkt/bazel,meteorcloudy/bazel,ButterflyNetwork/bazel,aehlig/bazel,perezd/bazel,bazelbuild/bazel,katre/bazel,aehlig/bazel,cushon/bazel,bazelbuild/bazel,perezd/bazel,aehlig/bazel,ulfjack/bazel,akira-baruah/bazel,ButterflyNetwork/bazel,katre/bazel,safarmer/bazel,cushon/bazel,perezd/bazel,perezd/bazel,ButterflyNetwork/bazel,twitter-forks/bazel,safarmer/bazel,cushon/bazel,cushon/bazel,ulfjack/bazel,twitter-forks/bazel,dslomov/bazel,dslomov/bazel,dropbox/bazel,safarmer/bazel,davidzchen/bazel,davidzchen/bazel,davidzchen/bazel