YARN-2940. Fix new findbugs warnings in rest of the hadoop-yarn components. (Contributed by Li Lu)
(cherry picked from commit d468c9aaf15e977f12e6214b47996412c907e069)
YARN-2937. Fixed new findbugs warnings in hadoop-yarn-nodemanager. Contributed by Varun Saxena.

(cherry picked from commit 41a548a916d4248164cb9495320f123ec215d70e)
YARN-2946. Fixed potential deadlock in RMStateStore. Contributed by Rohith Sharmaks
(cherry picked from commit 4f18018b7abb405f38d269da096ec9fd80c81d9a)