liblog: minimum_log_priority should be atomic

In case multiple threads try to reference this variable while it is
being set, it should be atomic so that all threads always see a valid
value.

Bug: 150898477
Test: liblog, libbase unit tests
Change-Id: If6c9e291f2471b96a752dc6e76e3e63458b71391
1 file changed
tree: 3a9efb7da6a7133ad9b5c252efd4b43d724fc78e
  1. liblog/
  2. logcat/
  3. logd/
  4. logwrapper/