MediaSet: Do not release lock, unlock it instead
MediaSet: Do not release lock, unlock it instead

Change-Id: Ib99c2451452eeaaa4fddfd41c80d8f95230305db

Kurento/kms-core,TribeMedia/kms-core,ESTOS/kms-core,shelsonjava/kms-core,TribeMedia/kms-core,TribeMedia/kms-core,ESTOS/kms-core,shelsonjava/kms-core,shelsonjava/kms-core,ESTOS/kms-core,Kurento/kms-core,TribeMedia/kms-core,shelsonjava/kms-core,ESTOS/kms-core,Kurento/kms-core,Kurento/kms-core