veyron/services/config/lib: Fix race

This commit fixes the following race as detected by go test -race:
==================
WARNING: DATA RACE
Write by goroutine 7:
  veyron/services/config/lib.(*configService).Stop()
      /Users/ashankar/veyron/veyron/go/src/veyron/services/config/lib/config.go:80 +0xa5
  veyron/services/config/lib.testConfig()
      /Users/ashankar/veyron/veyron/go/src/veyron/services/config/lib/config_test.go:184 +0x1842
  veyron/services/config/lib.TestConfig()
      /Users/ashankar/veyron/veyron/go/src/veyron/services/config/lib/config_test.go:205 +0x17f
  testing.tRunner()
      /Users/ashankar/veyron/environment/go/src/pkg/testing/testing.go:422 +0x10f

Previous read by goroutine 31:
  veyron/services/config/lib.(*configService).watcher()
      /Users/ashankar/veyron/veyron/go/src/veyron/services/config/lib/config.go:301 +0x4bd

Change-Id: I4f55c4075630ede69644ce2ced7930681191d6f0
1 file changed
tree: 2e28761dfcfdab69f2c8fb4c32007a000ac96015
  1. examples/
  2. lib/
  3. runtimes/
  4. security/
  5. services/
  6. tools/